I polished an entire group last week. Disassembled the Dia Compe calipers and everything. In my stainless steel sink I wetsanded every part with 400, 800, 1000 then 2000 grade (some smaller brake parts I just used 2000). Then I polished it with Brasso. That didn't give me the chrome look I wanted so I bought some Blue Magic polish. It almost is magic, the results were amazing.

Before, the post was scratched to hell:



After. It looks even better in person, almost chrome looking: