Wet & Forget Outdoor Cleaner in the ready to use version with included sprayer is ideal for quick application to small surfaces. Apply generously to a dry surface on a cool dry day. That’s it! Just wet it and forget it. Wet & Forget Outdoor eliminates black and green stains caused by moss, mold, mildew and algae without any scrubbing, power washing or using bleach. Wet & Forget Outdoor goes to work with the wind and rain to gently clean the surface over time.