Electrical Cleaners?

For bulb contacts I use a brass gun bore brush on a drill slowly. For others that I can physically touch I use fine sandpaper strips or emery cloth. For stuff that I can't see or reach I use electrical contact cleaner spray, it's safe to use on electric motors, contacts, etc.. and leaves a very tiny bit of contact lubricant to help prevent corrosion. The can I have I picked up for around $7-8 at the parts store.