There is a good thread running regarding heat sealed connectors. My question concerns whether there are good corrosion preventing compounds that can be put inside the crimp. Specifically, I had trouble with a connector on deck that was chronically wet and would corrode inside, and between the ring and the terminal. I took to putting a very heavy water proof grease in both areas, and the problem is gone. However, using grease in a location (main panel or sub-panel, for example) where a fire is possible is another matter. The amount of grease required is, of course, ridiculously small after you clean-up.