Homebrew PCBs

The question here has been a replacement for the persulfate.

 From Wikipedia, the free encyclopedia
"The term *persulfate* (sometimes known as peroxysulfate) refers to ions 
or compounds containing the anions SO2\u2212
5 or S
2O2\u2212
8.    . . .   These salts are strong oxidizers."

I'm not sure what the copper reaction with the persulfate would be, but 
it obviously doesn't involve HCl, and since the persulfate is an 
oxidizer, won't require H_2 O_2 .  If you use the CuCl or FeCl etchants, 
you can't avoid HCl in the process - it's part of the reaction.

It's been too long (65+years) since my high school/college chemistry!

Norm