MudDuck

Don't power wash it anymore with high pressure. Sounds like you over did the oxalic, that is supposed to be for neutralizing the other stripper acid and lightening up the wood but was supposed to have been wash off too. Nothing you can do now. Use Armstron Clark stain which is very user friendly you can't screw it up. You will need to light sand the wood if it looks "fuzzy" with a orbital varible sander polisher. Research Osborn brushes here. Go to Armclark.com for stain. Tell them Randall with Blue Ridge power wash in NC sent you. They will take care of you. Let me know if you have any more questions. NO HIGH PRESSURE or bleach on wood! Let the chems do the work then rinse them off with the crap on the wood.