Just an fyi, a common misconception is that dielectric grease improves the conductivity of an electrical connection. Dielectric grease is an insulator. Its main purpose is to prevent corrosion by sealing out moisture. It can also help prevent fretting, a pitting of the contact surface due to vibration.

If the connection being made is a loose sloppy fit dielectric grease won't help, it will actually make it worse. The blades of your plug need to fit tight enough in the socket to displace the grease from the contact area.

If you look closely at the blades of an rv plug some of them are not solid but made of layers of thin metal. Take a small screwdriver and spread these layers apart. This can help the plug fit a little tighter in a worn out pedestal socket.

I agree with Josh that using a dielectric grease is a good preventive measure. Go ahead and smear it all over your battery terminals, but use it sparingly in a plug and socket application.