One word of caution. (Ok, actually a couple.) The original thread was about removing scratches in stainless steel. And from what I've heard, HMP is the way to fly. But, that would mean one was leveling (to remove scratches) the actual base metal.
I believe the second question was around removing fine scratches in chrome. Here's the big but - chrome is a plated coating and not very thick. If you go too crazy removing scratches, you might just end up going through the chrome. And I should add that the chrome plating on anything isn't all the same thickness. Due to what are called "high and low current density areas", you have variations in the thickness of the plating.
So I'd be a little careful about going too crazy with a metal polish made for polishing a base metal on any plated surface.