While waiting for the C96 'test' piece to soak, I browsed the Web and found sites stating that Phosphoric acid would etch nickel/chrome...Various household products were mentioned...I don't have any of them...But Naval Jelly has Phosphoric acid in it (a very mild solution)...So I brushed that on one of the nickel plated Mec-Gar mags and left it overnight...The pic below shows how it affected the nickel...Not really etched...More like tarnished...
Not
exactly what I'm looking for...But it is a step in the right direction...