So my hitch rattled. 2" receiver (started with a tri-ball hitch, had some serious slip in it. It was way to high for the trailer & camper. Got a 5" drop hitch. Still had slop but better for trailer, still need it lower for camper (adjustable hitch ordered).
All of these rattled like crazy in the receiver. There was nearly 1/8" total slop on the receiver tube.
My $4 fix was to use a 3 1/4" exhaust clamp and I looped the top part over the lip of the receiver and the bottom flange under the hitch. Tightened the nuts and viola! No more slop!
Still can access the safety chain loops and plug.
Quiet as can be.
Napa part #733-5753

Cool, That works
I fill receiver with coatings of rubberized undercoat, same with hitches. Builds up quick and has held up for a good while. Easy to touch up with more.
I do the same on d hooks and anything else that might rattle.

Welder :-)

Paper

Old bicycle inner tube

or thin wood chips.

Well, hey, the welder idea prevents theft