Yeah, I tried that method.. but, for some reason, it takes ALOT of time.. granted that I did not try in a etching tank.. only in a bold with two parts H2O2 and 1 part HCL.
Would if be faster in a tank with air bubbles on the the board ?
for now, I went back using Ferric chloride + citric acid + water (The Edinburgh Etch). Works good.