Hey Steve Gunn...What did you decide on, citric or oxalic?
I went downriver and watched Tony C strip and brighten two decks yesterday. He used citric to brighten and it did an excellent job of brightening the wood. It was very noticebale in less than 10 minutes while the wood was still wet, too. I will also note that he rinsed the brightener off and it only took about 5 minutes.
I am still way too new to have an opinion on the "To rinse or not to rinse...that is the question!" dilemma. I do have to wonder what happens to the crystals in a powder mix after it is sprayed on the wood. If you poured sugar into a glass of water, stirred the bejeezuz out of it, and poured it onto a flat surface, I can guarantee there will be crystals lying on that surface when it dries. What is different about powder acids?
Please do not misconstrue...I am neither for nor against rinsing yet, just tryin to think logically.
By the way, I just received the Wood Britener from Sun Brite, which has a "mixture" of acids. I'm guessing it is similar to the Citrolic acid from the Grime Scene. I haven't used it yet, but will be next week when I tackle my deck jobs after I build my new deck sprayer system (goodbye pump ups!).
I've taken the liberty of posting a couple of pics of Tony aka APlus aka DeckMaster (I gave him that moniker). In this picture. He had a maniacal laugh as he washed the Penofin off this deck like a hot knife through warm butter!