Cleaning bulkhead connectors

It's not that hard to back the terminals out and clean them individually.
The female terminals can't easily get an abrasive under the rolls without messing up the tension.
Most recently I've been using De-oxit followed by a quick dry electrical cleaner.

Each bulkhead connectors has a foam seal - DMT sells new ones.

As far as dielectric grease goes, I've been using it on some connectors but am not convinced its great for moisture protection. I've seen green oxidation in the grease when taking them apart a few years later.