Jim said:

Ferric Chloride may be safer than Muratic Acid

Not even close

Can you say more?

Let me first say I don't work with either on a regular basis - I'm sure
you have LOTS of experience with Ferric Chloride.

But if you've etched copper with the Muratic Acid/Hydrogen Peroxide
solution you're advocating, it will have lots of copper ions in it, and
it's the copper that makes spent Ferric Chloride a Hazardous Waste.
http://www.mgchemicals.com/techsupport/ferric_faq.html

Make no mistake, I'm not presenting Ferric Chloride as benign - it's
clearly not:
http://www.jtbaker.com/msds/englishhtml/f1080.htm

Neither is Muriatic Acid:
http://householdproducts.nlm.nih.gov...ds&id=16009010

Why do you see Muriatic Acid as less trouble? I'm genuinely curious...

Highest Regards,