A couple of cleaning tricks regarding brass and gold parts:
After you're through polishing the brass that's NOT lacquered (basically everything except the bird/Emperor Ming tailpieces), rub on a thin film of Alberto VO-5 (yes, the old school hair cream in the gold toothpaste tube). This stuff is organic and harmless to everything on the bass and will keep it shiny a LONG time, unless you're doing lots of sweat-like-a-pig gigs. Just a LITTLE, where it only feels smooth afterward, NOT greasy.
For gold plated parts where you CAN'T use Flitz, Brasso, etc., (Brass polish WILL wreck gold plate on tuning keys, back plates, etc.), use a good car wax (Meguiar's, Mother's,etc.), but NOT the polish or wax/polish as they have small amounts of fine grit to remove swirls. This works great for that kind of cloudy fingerprint residue on the tuning key buttons, for instance, that you can never seems to wipe completely off with a dry rag. Plus if you have a gloss/clear coat instrument finish, it's fabulous guitar polish as well.
J o e y