I have some anti seize high temp super thick grease that I put on my rack bolts, and from my personal experience over the years, it would appear that it helps reduce vibration caused loosening, which I have much much less of while touring, than what I recall from years ago when I didnt do this.
I equate it to that "rubbing in wax" technique, which I have never done because I was too lazy to go buy a block of wax, simply cuz I had the thick grease, and I had dirtied up all the rack bolts and therefore was too damn lazy to clean them and the bikes threads of it, as I figured it would be best if I were to try the wax thing.
ps, this automotive stuff is almost peanut butter thick.