| Some people have suggested that, since silicone grease is an insulator, it can not be used on electrical connections. This view is incorrect. 
Imagine looking at a tiny section of the metal surfaces where they touch. They are clamped tightly together. The surface appears smooth to the human eye but, under a microscope, you can see "mountains and valleys" and only the peaks of the "mountains" make contact. When moisture and oxygen get inside the gaps ("interstices") between the mating contact surfaces, an electrochemical reaction causes corrosion. (Even more so for car battery terminals where sulphuric acid vapour is present and heat speeds up the chemical reaction). 
The corrosion products swell and push the surfaces apart so that contact is eventually lost or very poor. 
By introducing silicone grease between the new shiny mating surfaces, we exclude oxygen and moisture but sharp "mountain peaks" bite through the grease to maintain the same electrical contact as before. But this time it will last indefinitely because the grease keeps moisture and oxygen out. | 
