 They sell deck cleaners and deck brighteners, and it's definitely worth the money to do that and follow the instructions. You'll probably get an extra year out of your stain. Good point. And Bayer makes a deck cleaner, too. Yeah, good point. Yeah, they do. Great idea. The other thing, if you're going to use a pressure washer on a wood deck, you've got to make sure the pressure's down. Otherwise, you could zip a hole right into that wood or a groove.