Last Updated on September 1, 2026 by Sam Wood Worker
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A dirty deck does not always need the strongest cleaner on the shelf. It needs the right cleaner for the stain and the surface.
Green algae needs a different approach from grill grease. Weathered wood needs different preparation from capped composite decking. Choose the wrong product and you may do a lot of scrubbing without solving the real problem.
After comparing manufacturer directions, product information, safety documents and common buyer feedback, Simple Green Oxy Solve is the best all-around choice in this guide. It is made for decks and fences, works with manual cleaning or a pressure washer, and carries the EPA Safer Choice label.
However, it is not the best answer for every job. DEFY Wood Cleaner is a better fit when bare wood needs preparation before staining. Wet & Forget suits homeowners who want gradual removal of organic growth with very little work. Oil Eater is mainly useful for greasy spots. Kärcher Multi-Purpose Detergent makes sense when a compatible pressure washer is already part of the plan.
This is a research-based comparison. Results can change with the deck material, age, finish, stain type and cleaning method. Read the current label and test the cleaner in a hidden area before treating the whole deck.
The Best Deck Cleaners at a Glance
| Deck cleaner | Best for | Application | Main limitation |
|---|---|---|---|
| Simple Green Oxy Solve | Best overall for regular deck cleaning | Brush, sprayer or pressure washer | Heavy stains may need light scrubbing |
| DEFY Wood Cleaner | Bare wood before stain or sealer | Pump sprayer or brush, followed by rinsing | Intended for wood preparation, not simple spot cleaning |
| Wet & Forget Outdoor | Mold, mildew and algae stains with no scrubbing | Pump sprayer | Results are gradual, not immediate |
| Oil Eater Original | Grill grease, oil and greasy food marks | Diluted spot treatment and brush | Not a complete mold or weathering treatment |
| Kärcher Multi-Purpose Detergent | General dirt with a pressure washer | Compatible pressure washer | Pressure can damage wood when used incorrectly |
1. Simple Green Oxy Solve Deck and Fence Cleaner — Best Overall
Simple Green Oxy Solve is the most balanced option on this list. It is designed for decks, fences, pergolas and similar outdoor surfaces. The oxygen-based formula is made to lift dirt and stains linked to mold, mildew, moss and algae without chlorine bleach.
It can be applied with a pressure washer or used manually. For manual cleaning, Simple Green currently directs users to mix one measure of concentrate with 20 measures of water. Apply it to a manageable section, allow a short dwell time, lightly scrub dirty areas and rinse before the cleaner dries. Always follow the directions on your bottle because formulas and instructions can change.
The EPA Safer Choice recognition is a useful advantage. It means the formula has been reviewed against the program’s ingredient and performance requirements. It does not mean careless use is harmless. Keep children and pets away during cleaning, protect nearby plants as directed, avoid runoff into places where it should not go and rinse the deck properly.
Why it stands out
It covers the problems found on many everyday decks: surface dirt, mud and organic staining. It is also more flexible than a cleaner that only works through a pressure washer.
Imagine a composite deck with muddy footprints near the steps and light green staining along the shaded railing. This is the type of mixed, routine cleaning job where an oxygen-based deck-and-fence product makes sense.
What to consider
This is not a stain stripper. It may not remove an old coating, deep tannin discoloration or years of gray, damaged wood fibers. Those jobs can require a dedicated wood cleaner, brightener or finish remover.
Best for: Routine cleaning of compatible wood, composite, vinyl and masonry surfaces.
Not ideal for: Removing an old deck coating or treating a deep oil spill.
Simple Green Oxy Solve Deck and Fence Cleaner
2. DEFY Wood Cleaner — Best Before Staining
DEFY Wood Cleaner is a more focused choice. It is made to prepare exterior wood for a new stain or sealer. Its sodium percarbonate formula, often called oxygen bleach, helps remove dirt, mildew stains and loose weathered gray fibers from bare wood.
That difference matters. A maintenance wash tries to make a deck look cleaner. Surface preparation tries to leave the wood ready to accept a finish. These are related jobs, but they are not always the same job.
A homeowner may have a cedar or pressure-treated deck that looks gray but is not covered by a solid coating. The goal is to apply a penetrating stain after cleaning. A dedicated wood cleaner such as DEFY is more relevant in that situation than a slow, leave-on algae treatment.
The manufacturer recommends following the wood cleaner with its brightener as part of its preparation system. A brightener can help neutralize the cleaner and improve the appearance of some wood. Use the complete process required by the stain manufacturer, not a mixture of unrelated online tips.
DEFY Wood Cleaner
Why it stands out
It has a clear purpose. It is meant for exterior wood restoration and coating preparation rather than being a general household degreaser.
What to consider
It is not the right choice for every surface. Composite decking and factory-finished surfaces may have different cleaning requirements. It also will not automatically remove every old stain or paint layer. A finish remover may be needed when a coating remains.
Best for: Bare or weathered wood that will be stained after cleaning and drying.
Not ideal for: A quick wash of capped composite decking or a small grease spot.
Buying note: Add your current DEFY affiliate or retailer link here if you use one.
3. Wet & Forget Outdoor — Best No-Scrub Option
Wet & Forget Outdoor follows a different idea. Instead of cleaning the deck immediately, it works gradually on moss, mold, mildew and algae stains. The concentrate is diluted and sprayed on a dry surface. It is then left in place according to the label. Weathering helps remove the dead growth over time.
There is no scrubbing or pressure washing in the normal application process. That makes it appealing for a large deck or a shaded area where green staining keeps returning.
The tradeoff is time. This is not the product to choose when the deck must look clean before a party in two days. Manufacturer information explains that improvement is gradual and stubborn contamination may take much longer than light growth.
Think of the north-facing side of a deck that stays damp after rain. The boards may develop a green film even though the sunny side looks fine. A slow outdoor treatment can suit that repeated organic staining better than aggressive pressure washing every few months.
Wet & Forget Outdoor
Why it stands out
Very little physical work is required after application. It can also be used on many exterior surface types when the label permits them.
What to consider
Wet & Forget is not a complete preparation system for refinishing wood. If you plan to stain or seal the deck, follow the coating manufacturer’s cleaning and preparation directions. The surface may need a different cleaner, rinsing, brightening and a specified drying period.
The wet product should also be kept away from people, pets and plants as directed. “No scrub” does not mean “no precautions.” Wear the protection listed on the label and control overspray.
Best for: Gradual treatment of organic staining on compatible outdoor decking.
Not ideal for: Same-day results, grease marks or final preparation before staining.
4. Oil Eater Original Cleaner and Degreaser — Best for Grease Spots
Grill grease is not the same as algae. It can soak into porous wood and leave a dark spot even after the surrounding dirt is gone. Oil Eater Original is a concentrated cleaner and degreaser made to break down oily grime on washable surfaces.
Its best role on a deck is targeted cleaning. For example, a few greasy drops may appear below a grill or around an outdoor cooking area. Treating that small section with a suitable dilution is more sensible than applying a powerful degreaser across the entire deck.
Start with the manufacturer’s dilution guidance and a hidden test area. Finished wood, stained boards and some composite surfaces can react differently. Do not leave a strong solution sitting on the deck or allow it to dry unless the label specifically directs you to do so. Rinse thoroughly.
Oil Eater Original Cleaner and Degreaser
Why it stands out
It addresses a problem that normal deck washes may struggle with. The concentrate can also be diluted for different approved cleaning jobs.
What to consider
Oil Eater is not a dedicated wood-restoration product. It will not replace a mildew cleaner, wood brightener or coating stripper. A degreaser may also change the appearance of an existing finish, which is why a test patch is important.
Old oil that has soaked deep into unfinished wood may not disappear completely. Cleaning the stain early gives a better chance of improvement.
Best for: Small grease, oil and greasy food stains on a compatible surface.
Not ideal for: Whole-deck algae treatment or preparation of weathered wood for stain.
5. Kärcher Multi-Purpose Pressure Washer Detergent — Best with a Pressure Washer
Kärcher Multi-Purpose Pressure Washer Detergent
Kärcher Multi-Purpose Detergent is made for pressure-washer cleaning of outdoor surfaces, including decks where the product label permits it. It is a practical choice for general dirt when you already own a compatible machine and want a detergent designed for that delivery system.
The detergent is only part of the job. Pressure, nozzle choice, distance and technique have a major effect on the result. A strong, narrow jet can cut soft springwood, raise fibers and leave permanent lines across a wood deck.
Use the lowest effective pressure. Begin in a hidden area. Keep the nozzle moving and maintain the distance recommended by both the decking and pressure-washer manufacturers. Work with the grain where appropriate, and never assume that a setting safe for concrete is safe for cedar or pressure-treated lumber.
A pressure-washer detergent can be useful on a large deck covered with ordinary soil and tracked-in mud. It is less helpful when the real problem is a failing finish, embedded rust or deep grease.
Why it stands out
It integrates with compatible pressure-washer detergent systems and is intended for broad outdoor cleaning.
What to consider
The machine can cause more damage than the detergent if it is handled poorly. Some composite decking manufacturers also limit pressure settings and nozzle types. Their instructions should come first.
For natural wood, Kärcher also sells more specialized wood-cleaning formulas in some markets. Check product availability and make sure the exact formula is approved for your surface.
Best for: Fast cleaning of broad, compatible deck surfaces with an existing pressure washer.
Not ideal for: Delicate wood, local grease treatment or decks with loose coatings.
How to Choose the Right Deck Cleaner
Match the cleaner to the problem
Start by identifying what you see.
- Green or black organic staining calls for a product labeled for mold, mildew, moss or algae stains.
- Gray bare wood may need a wood-restoration cleaner and possibly a brightener.
- Grill grease needs a compatible degreaser used as a spot treatment.
- Peeling stain needs removal and surface preparation, not a routine wash.
- Dirt on capped composite decking should be cleaned according to that board manufacturer’s care guide.
A darker area is not always mold. It may be tannin staining, rust, trapped moisture, old coating or wood decay. Cleaner will not repair rot or a structural problem.
Check the deck material
Natural wood, pressure-treated lumber, cedar, hardwood, PVC and capped composite do not all respond in the same way. Even two composite brands may publish different chemical and pressure-washing limits.
Read both sets of directions: the cleaner label and the decking care guide. If they conflict, do not guess. Ask the manufacturers before applying the product.
Decide whether you are cleaning or refinishing
Routine cleaning removes normal surface dirt. Refinishing preparation may need to remove weathered fibers, mill glaze, water repellents or an old coating. It may also require a separate brightener.
If a new stain is planned, use the preparation products and drying time specified by that stain manufacturer. A deck can look clean while still being unsuitable for coating.
Think about runoff
Before starting, move furniture and sweep the deck. Cover or wet nearby plants as directed. Protect metal, glass, siding and surfaces that may react with the cleaner. Keep the solution out of ponds and storm drains unless the label clearly allows the intended use.
Never mix deck cleaners. Combining chlorine bleach, acids, ammonia or other chemicals can create dangerous reactions.
How to Clean a Deck Without Damaging It
- Read the cleaner label and the decking manufacturer’s care instructions.
- Check the weather. Avoid conditions that make the solution dry too quickly or wash away too soon.
- Remove furniture, planters and loose debris.
- Protect people, pets, plants and nearby materials as directed.
- Test the cleaner in a small, hidden area.
- Mix only the amount and strength stated on the label.
- Work in small sections so the product does not dry unless it is a leave-on formula.
- Use a soft or medium non-metal brush if scrubbing is allowed.
- Rinse as directed and prevent dirty solution from drying on nearby surfaces.
- Let wood dry fully before applying stain or sealer. Follow the coating maker’s moisture and drying requirements.
Can You Pressure-Wash a Wood Deck?
Yes, many wood decks can be pressure-washed carefully. But more pressure does not mean better cleaning.
Too much force can carve lines into softwood, raise the grain and force water into joints. Use a wide fan pattern and the lowest effective setting. Keep a steady distance and test first. Never use a concentrated zero-degree nozzle on deck boards.
If the decking manufacturer does not permit pressure washing, use its approved manual method instead. Damaging the surface may affect appearance and warranty coverage.
Frequently Asked Questions
What is the best deck cleaner overall?
Simple Green Oxy Solve is the best all-around choice in this comparison. It is made for deck and fence cleaning, can be used manually or with a pressure washer, and is suitable for several common outdoor surfaces when used as directed.
What is the best cleaner for a wood deck before staining?
DEFY Wood Cleaner is the better choice here because it is designed to prepare exterior wood for refinishing. Depending on the stain system and condition of the wood, a brightener or finish remover may also be required.
What removes green algae from decking?
Wet & Forget suits gradual, low-effort treatment. Simple Green Oxy Solve is better when you want to clean and rinse the deck during the same session. Confirm that the chosen product is approved for your exact decking.
What is the best way to remove grill grease from a deck?
Blot a fresh spill quickly. Then use a compatible degreaser such as Oil Eater on a small test area, following its dilution and rinsing directions. Deep oil stains in porous wood may remain visible.
Is an EPA Safer Choice cleaner completely safe?
No cleaner should be treated as risk-free. Safer Choice identifies products that meet EPA program criteria, but users must still follow the label, use required protection and keep people and pets away during application.
How often should a deck be cleaned?
Many decks benefit from a gentle cleaning about once a year, but shade, trees, rain, foot traffic and local climate can change the schedule. Clean spills promptly and remove leaves before they trap moisture.
Can deck cleaner harm stain or sealer?
Yes. A strong cleaner or degreaser may dull, lighten or remove part of an existing finish. Test first and check the coating manufacturer’s maintenance instructions.
Final Verdict
There is no honest winner for every type of deck stain.
Choose Simple Green Oxy Solve for balanced routine cleaning. Use DEFY Wood Cleaner when bare wood needs proper preparation before a new finish. Pick Wet & Forget for slow, no-scrub control of organic stains. Keep Oil Eater for small greasy areas. Choose Kärcher Multi-Purpose Detergent only when a compatible pressure washer and careful technique suit the deck.
The best result comes from matching the cleaner to the surface and the stain. Test first. Follow the label. If you plan to refinish the deck, follow the stain or sealer manufacturer’s full preparation instructions as well.
Research Sources
- Simple Green Oxy Solve Deck and Fence Cleaner: product directions
- U.S. EPA Safer Choice product data
- DEFY Wood Cleaner: manufacturer information
- Wet & Forget: how to clean a deck
- Oil Eater: cleaning guidance
- Kärcher: pressure-washer detergents
- STAR BRITE Non-Skid Deck Cleaner: intended surfaces and directions