I've been asked to quote a brazilian wood deck and didn't know if softwashing with a 1-2% solution then neutralizing with bleach wash would be safe.  It has a gray discoloration which I guess is normal after having not been cleaned in a few years.  I've seen other posts about using oxalic acid and sodium hydroxide to clean and brighten, but having only cleaned stained or painted decks, I don't know if I should steer clear of this one.  Thanks for the help.