Restoration Question

I have recently acquired a couple of build PC boards that are not solder masked. There is some oxidation, ranging from minimal to mild (mild being the not quite green, but a very hard oxide, as if the tin had reacted with something else). Anyone got any good ideas on cleaning these? I'd like something non-submersible, since one of the boards contains keyswitches. I have plenty of experience cleaning unbuilt boards. Normally, I'd just hit them with some super fine steel wool, or buff them with 20lb paper. And I've repaired boards, but usually to get them working, not to restore their aesthetic appeal. I've considered using a baking soda solution and a stiff bristle brush. This should neutralize any corrisive elements, and the baking soda might be abrasive enough to remove the oxides without damaging the board. It would wash off easily enough with water, and I could protect the switches during that process. Anyone got any ideas or standard procedures for this kind of thing? --JOhn