Hey Farrier, I use dialectric grease like toothpaste.....every connection, even inside the battery box...
On my new connections, like inside the plug, I jam dialectric inside, then put any booties over the outside, then seal outside with marine goop...let dry, and then outer coat external connections with more dialectric
Every 5-7 trips, I clean and re-grease just the outside connections.
after about a year, my connections look like brand new...
I think I got the grease at an autosupply place in a huge tube about the size of marine goop
cowboybill