Dichromate bleach--is sulphuric acid the only acid that will work or will any sufficiently strong acid with with sodium dichromate in particular or in general potassium or ammonium dichromate. If so, why? or if no, why and what else is worth trying, particulary acetic acid, since it's readily available. I've been able to use reversal bleach which is quite diluted from the recommended concentrations (this is the sulphuric acid stuff). My question is--can ANY sufficiently strong acid work? Are they any that should be avoided due to chemical reactions? Any people tried this and had any results good or bad or catastrophic?