Achow,
You can try to make a “Super Pickle” type solution simply by using
the Rio Grande pickle and mixing it with hydrogen peroxide instead
of plain water and re-soaking your bracelet. It is usually pretty
effective at removing the fine copper plating the can sometimes
deposit on your sterling when nickel or steel somehow makes it into
your pickle pot. I have used this method to clear the copper plating
off pieces myself, and it works pretty well most of the time.
This used to happen all the time to students during art school when
a beginning metals student would use cheap steel tweezers instead of
copper ones in the “communal pickle pot”. It saves a ton of sanding
most of the time.
BTW, you can also use this effect to your advantage; I have often
used my old dark blue (saturated) pickle to cover silver solder
seams on copper pieces by purposefully placing the piece in a jar
with steel wool or an old worn out steel file. Essentially using
that plating process on purpose. It’s a great trick to cover
unsightly silver solder seams if they visually interrupt a copper
design.
Hope this helps,
Teresa