This would not be a bad tool set to have on hand for pin cleaning, and good for other small filing or electronic device decorrosion tasks (Find at Amazon):
Innovative Products 8042 Female Bullet Connector Cleaner Set - 12 Piece , Red .
Other “kits”, not quite as spendy, are available. I have one for trailer connectors, but the tools are all much too large for the cylindrical multi-pin type conversed here. There are also tools designed for removal and replacement of pins and sockets in their cylinders if ever necessary.
Carl’s suggestion of dielectric grease on pins, or any reassemblage, is well advised, or use DeoxIT (7.4ml bottle); for automotive, ambient air-exposed applications, the grease is probably best. A can of electronics cleaner spray is handy, and Corrosion-X spray on air-exposed connection in any bay works well.
Joel