More important the dielectric grease are clean plug prongs. Use Emory cloth or sandpaper and clean the prongs first, then if you want to lubricate them use the dielectric grease. Only a light coating.
On the 12 volt side, After cleaning my battery connections, I will coat them with a light coating of vasoline. Don't need much, the vasoline melts and coats the connector and terminal and prevents the formation of corrosion. I will wipe off any excess that flows onto the battery over the next few months.
06 Hurricane 34FT WH W20 Chassis 8.1L 120K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, KVH R5 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee