Had my trailer in for some work on the electrical system. Before I left the tech said, let me come out and put some diode grease on the electrical connections. He said, it will make them slide in and out better and it will improve the conduction. I said, "better than WD40?" He said, that's not a good thing to use. Once it dries out it actually might lead to rusting. So, while we were standing there I said what about the ball hitch? Grease that puppy up? He said, "no we recommend dry" Never heard that before. Was wondering what everyone's thoughts were on it.