How to Clean & Treat Your Deck to Make It Look New - YouTube Jun 26, 2013 . One busy family, one dull deck. (And the green spots - stains from mildew!) Watch how easy it is to clean and treat the deck to make it look brand-new. HGTV/diy network star Jeff Wilson walks the family's Mom through the basics of cleaning and waterproofing a deck with Thompson's Water Seal products to..