Ever try using electrolysis for cleaning metal? YouTube has plenty of videos- it's used for all kinds of restorations, like hand planes, saws, car parts, etc. If you want to try using mechanical shock, insert an allen wrench in a single saddle on a block of wood and smack it with a small hammer- not enough to damage it, but the corrosion can break free.
The nut on my SD Curlee was a lost cause, so I made a new one and the BadAss II bridge had been cut badly, plus it doesn't have the correct spacing for a medium scale bass, so it was pretty bad. The previous owner wasn't big on maintenance and apparently knew nothing about setup. His sound wasn't all that great, either.
I use PB Blaster for penetrating oil- best I have found.
For cleaning Brass and Bronze, I like ScotchBrite- I tend to prefer a soft glow or satin finish on those metals- the white pads aren't really abrasive, the next is blue, which is also sold for cleaning non-tick pots & pans. The abrasiveness increases once you get into the green, gray, brown and red but 3M has a grit comparison chart online.