Can Nickel Plating be removed?

I have a customer who purchased a nickel (maybe rhodium) plated
sterling silver chain from my store last year.

He recently returned to have it cleaned and I noticed that whatever
plating was on there, is starting to wear off.

I after several attempts at tumbling and polishing I have yet to
even “scratch the surface” of being able to make it shine again.

The plating is thick, and heavily scratched.

Triple-E won’t remove it. I am at a loss.

Is anyone familiar with any polishing agents or removal process that
can fix my problem?

This is my first post to the forum, and I hope I worded everything

Richard Aubin
Trek Jewellers

Nickel plating can be removed by reverse plating using a lead
cathode and around a 50% sulphuric acid bath at room temperature and
6 volts. ( from “Electroplater’s Handbook” by C.W. Ammen ) None of
the numbers are very critical. Any rhodium or gold plating over the
nickel is also removed. It will attack silver but only very slowly,
keep an eye on it. As I remember the current drops significantly when
the nickel is gone. The silver will have a frosted white surface
which responds well to tumbling with steel/stainless shot.