WD-40 is a penetrating oil and is corrosive (most people don' t know that). Use the lightest way possible. I' ve heard of aircraft mechs using pencil erasers on minor corrosion. Just use steelwool but nothing else. When you are done you can wax them if you don' t want to oil them.
I didn' t know that. Navy is right about the pencil eraser. You can color on the rust w/ the lead, then erase it right off. I' ve done it on rifle barrels before.