|Although there are a number of conductive greases, most are really not very conductive. Some are not conductive at all, but are just protective greases that prevent oxygen from corroding or rusting the contact surfaces. The best conductive greases are loaded with metal, preferably with silver. Those can be purchased from Chemtronics, MG Chemicals, Cool Amp, Grainger, and a few others. Look for the words "Silver" and "Conductive Grease". Unfortunately, even small quantities of this material can set you back over $20, but silver isn't cheap, so it makes sense.