I use the ACE Hardware Extra Strength semi-paste paint varnish and stain remover. It seems to leave the existing plating in place.

I used to use Zip-Strip back when it was in a black and yellow can. It was even harsher of a stripper and would strip off the remaining plating; not good.

I also have a cheapy Harbor Freight bead blaster that I would turn the psi down as to not strip off the hardware's plating.