Best way to clean electrical contacts?

Whats the best way to clean an oil soaked contact without doing any damage (or any more than what may have already been done). Normally I would just use contact cleaner and/or dielectric grease but this is different. Will a wire brush cause damage. Whaddya think before I go **** up some wiring.

Well I figured out the problem. The wires that go into the connector and then the ignition box were the culprit. Now I am very aware of the previous owner's hack job wiring. I already rewired the dash and interior. So the 4 wires off this connector were stripped and half covered in electrical tape that was falling off and the wires were covered in oil. Unreal. I just ripped all the **** off cleaned the wires, retaped them took the heat gun to them and cleaned it all up. The car is fine now.