NO WD-40 !!!!!!!!!!!!!!!!!!
Like the Vermouth in a good Martini, WD-40 should be kept in a locked closet when a gun is in the room.
The reason for using oil when removing (using steel wool, bronze wool or a penny as the tool) corrosion is to "float" off the particles. The oxides are harder than the "tool" and the oil prevents scratching.
I like to use an old brass shell casing. It is rounded enough to allow only a small surface to meet the steel of the part. The smallest area possible should be eroded.
Best,
John
