Keep your wife happy and season in a gas grill.Just like teflon fry pans. Great when new but crap in the long run. I'll stick with cast iron that re-seasons itself every time it's used. It'd be funny to see how a seasoned JJ ball performs. Just don't let the wife catch you!
If you want a teflon rod end they make those, but they aren't rebuildable.
I don’t think coatings are the answer other than to increase corrosion resistance. The problem is really how do you these certain kinds of earth from attacking the lubricant. Ideally some kind of seal/shield would be the answer but then the question becomes how?