Here is the MSDS for Sunnywash Deck Wash, I do not like the fact that it contains sodium hypoclorite as well as sodium hydroxide. The hypo is bleach not good for wood. I would use a deck cleaner containing citralic or oxalic acid. Redo it using Wolmans Deck Brightener mixed to the spec on the label. Be sure you apply uniformly to the surface with a spray bottle.