Wet & Forget safely and gently cleans moss, mold, and mildew stains on all outdoor surfaces. No special equipment is required to apply. The nonacidic, noncaustic formula contains no bleach. Results are visible one to two weeks after application, and rain reactivates the cleansing combination to flush away stains for up to a year. Wet & Forget, 888-727-8524, www.wetandforget.com. $29.99.
Clarity of Instructions 9.3
Overall Average 7.9