Actually oil is good. It keeps surface oxidation, which is insulating to electrons, from happening, although most antennas are chrome plated. Oil is an insulator but when there's metal to metal contact there is still an electrical connection and the oil lubricates the sections and puts a lighter load on the motor. The only problem is that it attracts dirt. I do regular cleaning and light oiling for maintance. I also put a dab of grease on connectors and battery terminals.