Maybe a better source of oxygen is sodium perborate. A while back, I accidentally stumbled upon this site while searching the topic of PCB etching,
http://catmacey.wordpress.com/projects/making-pcbs-with-simple-tools/etching-the-board/Note the statement, "It's the standard mix for sale here in Barcelona". I could not find any further reference to its use in PCB etching. I collected some notes on sodium perborate. Apparently it's widely used in non-chlorine bleach (e.g. OxiClean), but is in general considered a solid form of hydrogen peroxide. To wit:
(ref. forgotten source)
"Sodium perborate tetrahydrate is prepared by reaction of sodium
borate with hydrogen peroxide. Sodium perborate releases back
hydrogen peroxide, if dissolved in water. Its properties in
aqueous solution are practically similar to those of a solution
of hydrogen peroxide. Accordingly, sodium perborate is considered
as a solid form of hydrogen peroxide used as a strong oxidizing
agent in various industry including in detergent. In comparison
with solution of hydrogen peroxide, solid form of sodium perborate
compounds provide better conditions of stability and convenient
handling. Sodium perborate monohydrate provides a high available
oxygen content equivalent to 32% hydrogen peroxide - 50% more
active oxygen than the same weight of sodium perborate tetrahydrate."
The common product is tetrahydrate and I bought 1 lb. from here,
http://www.soapgoods.com/Sodium-Perborate-TetraHydrate-p-772.htmlI haven't tried it. I think you just make up a saturated solution for your hydrogen peroxide equivalent. I am still using the Edinburgh etch version of ferric chloride which incidentally is much faster than straight ferric chloride, but still nasty. When I use up my supply of this stuff, I am going to give CuCl a try with sodium perborate.
Baxter