I restored a brass cash register, and needed to find a way to get down and dirty with the excessive tarnish on it. Hand-polishing was way too difficult. I tried several different polishes and cleaners with mixed results, but because of the ornate surfaces, found it very difficult to do it properly.
Finally, I used Lysol Toilet Bowl Cleaner (blue bottle) to strip the old tarnish off. Made the project a piece of cake. Caution should be taken as the blue stuff is acid and strips the metal to the shine in a hurry, but you have to wash and rinse the metal repeatedly. Oh, and wear gloves...!
After it was cleaned, I applied MAAS metal polish by hand. After each part was completely polished, I used an aerosol automotive clear coat on all surfaces. One single light coat did it. Here's the result.