What is the best tweak?

Dweller- you should also use you cleaning treatment on the main ground connection to your home. Clean and polish the ground wire, clamp and ground rod.

I use a high speed 3M buffing wheel mounted on a bench grinder to deal with AC connectors and spade lugs.

Dweller- My home is 15 years old, and this year was the first time I cleaned the grounding contacts. I guess it depends on where you live and the water/salt content in the air. I treated contact area with Caig R5 Power Booster(try some of this on your plugs), so maybe I'm good for another 15 years.

PS- before you disconnect the ground clamp for cleaning, run a jumper/bypass connection, just to be on the safe side.