Is your wood deck looking winter worn? Laundry detergent can be used for more than just colors or whites. Here is a great outdoor use for your laundry detergent. As the weather gets warmer, you may want to clean all traces of winter from your wood deck. Powdered laundry detergent and hot water is usually enough to spruce up your winter worn deck. This mixture acts as an abrasive and a cleanser. To eliminate mildew from your wood deck, use a 10 percent bleach solution. Use a power washer for extra cleaning power, and finish with a thorough rinse for a bright summer deck.