I use these little plumbers acid brushes and contact cleaner
I saw those brushes at menards in plumbing. I use them mainly to dislodge/wash the dirt out of the connectors. Especially old dielectric grease.Oh used those exact brushes at work a few years ago. Not sure where you get them tho but can't be hard to find. I still think q-tips might work ok also, just have to make sure part of it doesn't get left....
I understand it’s an insulator but check out these instructions on the grease PakDo NOT put dielectric grease on the electrical contacts as the grease is an insulator.Fill with dielectric grease when you're done cleaning them to waterproof them. The best you can really do is use contact cleaner to clean them unless you have the correct tools to take them apart and clean the pins individually. Or maybe have teeny tiny brushes and the patience of a god, that would work also....