Using a plain steel
wire brush leaves minute pieces of steel
in the part being brushed. Makes for a wonderful rusty mess until all the little particles all corrode away. Might be able to passivate it with acid if you do use a ferrous wire brush.
Best thing is to have the plater galvanically remove the chrome then buff out the pitting before rechroming. Cheapest is just to live with it.
I'll never have anything powder coated again. Once corrosion
begins under it, it comes off in large blotches. When the corrosion
starts, it's never ending till all the powder coat is gone. Best to properly prepare the surface and paint
using the paint