Preventing corrosion on self tapper ground screw

[rreegg]

Got a little 4x8 trailer and the ground for the pigtail/wiring harness is just a self tapper screw going into the steel trailer frame, behind the ball coupler.

Any good ways to prevent corrosion on this surface/area?
Originally globbed some wheel grease over things which worked well but doesn’t seem like a long term solution, anything that’s better to set and forget?

Asking because accidentally pulled out the ground and had to redo things and haven’t put grease again

 

[Clb]

Nolox

Battery terminal grease.

Clean and dry under/inside then shoot it with cold galvanize.

 

[rreegg]

Good ideas thanks! Have some galvi spray and haven’t used noalox