Our technology thoroughly searches through the online shopping world, reviewing hundreds of sites. We then process and analyze this information, updating in real-time to bring you the latest top-rated products. This way, you always get the best and most current options available.

Winner
The Oxy Solve House and Siding Pressure Washer Cleaner is a liquid concentrate designed to clean various types of outdoor siding, including vinyl, aluminum, wood, brick, and stucco. It effectively removes stains caused by mold, mildew, algae, and moss, making it suitable for keeping Trex decks and similar surfaces looking fresh. The main cleaning power comes from peroxide, which breaks down grime without using harsh chemicals, resulting in a safer and more environmentally friendly option.
This non-toxic and unscented formula reduces the risk of irritation and is preferable to traditional cleaners that contain strong chemicals. Being a concentrate, it can cover a large area—up to 6,400 square feet when used with a pressure washer—allowing for efficient cleaning. Application requires a pressure washer, so some familiarity or equipment is needed, but this method generally provides a quicker and more thorough cleaning compared to scrubbing by hand.
Users have rated the product positively for its effectiveness and ease of use. It is specifically designed for siding and deck materials and may not be suitable for delicate surfaces. This cleaner is well-suited for homeowners seeking an environmentally safer and powerful solution to remove mold and mildew stains on outdoor deck materials like Trex, provided they have access to a pressure washer for application.
The Wet & Forget Xtreme Reach Hose End Refill is a liquid cleaner designed to remove moss, mold, mildew, and algae stains from outdoor surfaces like roofs, siding, patios, and decks, including TREX composite decking. It’s applied by attaching the refill bottle to a garden hose, allowing you to spray up to 30 feet away with either a concentrated jet or a wide fan spray. This makes it easy and convenient to cover large areas without heavy scrubbing or rinsing.
One of its main strengths is the low-effort application—just spray it on a dry, cool surface without rinsing, then let wind and rain gradually wash away stains. This can save time and physical work compared to pressure washing or scrubbing. It’s bleach-free and non-acidic, which reduces the risk of damaging TREX decking and is safer for the environment if used responsibly (avoiding water bodies and rinsing nearby plants). However, its cleaning action is slow and gradual, with light green stains clearing in 1-2 weeks, but tougher black or older stains may take several months to fully disappear. This means it’s not ideal if you want instant results. Also, heavy or porous surfaces absorb more product, so you may need multiple treatments for heavily stained decks.
The product covers up to 2,000 square feet per bottle and is unscented, which is nice if you prefer no strong smells. Its simple hose attachment and spray method make it very user-friendly for homeowners without special equipment. Wet & Forget Xtreme Reach is a good choice if you want a gentle, low-maintenance cleaner for TREX decks that works over time and is environmentally mindful, but it may be less suitable if you need fast stain removal or have heavy, deeply ingrained stains requiring immediate attention.
The 30 Seconds Outdoor Cleaner 5 Gallon Concentrate is a liquid cleaner designed to cover large outdoor areas, including Trex decks. It is an organic formula, which means it uses natural ingredients and is likely safer for the environment compared to harsh chemical cleaners. This makes it a good choice if you’re concerned about eco-friendliness.
The concentrate form means you need to mix it with water before applying, which helps you clean up to 1,000 square feet, making it cost-effective for bigger spaces. Being a concentrate requires some preparation and measuring, so it might not be as straightforward as ready-to-use sprays. Also, the large 5-gallon container is quite heavy (86 pounds), which might be inconvenient to handle or store.
If you want a strong, environmentally conscious cleaner for your Trex deck and don’t mind mixing the solution yourself, this product fits well. However, if you prefer something lighter or pre-mixed for quick use, you might find it less convenient.