Homebrew PCBs

> I was curious about the stuff sold for removing ferric chloride
> stains, so I looked up the Mega Electronics data sheet on the stuff
> they sell (its made by Bungard). Its simply oxalic acid crystals and
> rubbing with rhubarb leaves should work just as well, they contain
> oxalic acid. Its quite poisonous, BTW.

use the muriatic acid with hydrogen peroxide and does not remain 
residual, once used it is neutralized with of common bicarbonate