So, in light of he recent concern over the use of Brasso, I've been experimenting with other things. What I've found that works quite excellently is Tarn-X. So far I've used I to clean a few rather corroded carts that were in my junk/trade/donor cart bins with no side effect of any sort. It also requires nearly zero effort to be effective. Dip Q-tip, wipe contacts gently, corrosion literally dissolves, but good contact material remains.
I wanna give a more thorough testing before I wholeheartedly recommend it, but initial results seem very promising.