I use dielectric grease on my bulbs, plugs, trailer tow hookups etc. We have outdoor landscape lights that use automotive brake light bulbs and they are exposed to all kinds of weather. I can tell the dielectric grease really helps them continue working perfectly in inclement weather year round. Without the grease the connections get corroded and you have to twist to insert the bulb a few times to get them to work correctly. With the grease they just keep working great.