Any guidance on curing rust on the trailer hitch...

[Leon R]

Wirebrush + can of Rustoleum + repeat every two years

I fixed it for you .

Rustorium is junk, especially if you are starting out with rusty material .

To do it right, take it out, blast it and "POR15 it". Powdercoating will also chip away if any rust returns (which it often does).

[Y33TREKker]

I can second the POR15.

I used it on a trailer hitch I had on another vehicle years ago, and aside from a couple of spots that needed recoated later (I didn't clean the original surface well enough before the first coat) it worked very well.

Based on my experience, I'd suggest taking the hitch off so that any rusty spots can be cleaned properly with a wire wheel down to clean metal, then reinstalling it once the whole thing is properly coated and cured.