As part of a house cleaning we are cleaning a deck and replacing approx 60' of 5/4 x 6 treated deck boards. It was stained with sherwin williams deckscapes solid water borne stain. Stain is is good condition and only needs to be cleaned - not stripped. What would you recommend to clean with? Just standard mild SH/Greenwash and rinse well? How should I prepare the new deck boards that we are replacing?