I figured it must be silver and dropped it into the pickle pot. Bad
mistake. It is now partially copper plated. Is there a way to get
that copper plating off again?
Freshly mixed, never-before-used pickle (soldium bisulphate pickle,
like sparex or ph-down) will slowly remove it, especially if it’s
warm or hot, if it’s not too thick. Or, to that same fresh pickle,
add a bit of hydrogen peroxide (the stronger stuff you get at a
beauty supply store, not the very weak 2 percent solution sold as a
cleaner/antiseptic in the drug stores… Makes it considerably more
aggressive, but the mixed solution remains active like that for only
a day or two at most, at which point it’s once again ordinary
pickle. After use, the pickle/peroxide mix can be added back to your
regular pickle pot.