Cedar shake roof cleaning?

Tried searched and found a few different suggestions anywhere from m-1 deck/roof cleaner to oxygen bleach. What is the preferred product for cleaning cedar shake roofs? One section has a decent bit of moss the rest is just ugly discolored. Any suggestions on material and process?

So seems like oxalic acid, dwell and rinse. Will all cleaned areas need to be re-oiled?

no, you have to use something to clean it first depending on how bad

oops that should have said sodium percarbonate :sweat_smile: