Polishing media for corroded parts

I've got a couple of older guns that I'm working on. They are starting to show signs of corrosion on the bolts. These parts look to be stainless or have been plated with some sort of chrome. I'd like to use a dremel tool and some sort of polishing media to buff this corrosion out and restore these parts to there original shine. Is there any polishing media that you'd recommend for this job? I'd also like to buy it locally if possible.