You can give this formula a try. We sometimes use it to remove the
copper coating from silver that has been accidently pickled in an
iron contaminated bath by a student (So where did the iron come
1/2 Cup Hydrogen peroxide (3%) (same stuff they sell in the drug
store) 1 Tablespoon FRESH Sparex solution pickle or sulferic acid
Warm the peroxide up to 190 to 200 degrees, a small crock pot works
fine. Now add the tablespoon of FRESH pickle. Do not add more pickle,
this is only a catalyst. Place the items to be pickled in the warm
peroxide solution and agitate with a feather or plastic spoon. The
peroxide will bubble and this lets you know it is working. Check the
progress of your items after a minute, it won’t take long.
Afterwards let the peroxide solution cool and store it in a dark
brown bottle. The solution is still good as long as it bubbles when
used. No bubbles, the solution is spent. Neutralize it with baking
soda to dispose of the solution.