We must have bought 10 or so salt grinders in the last 10-15 years and none of them have lasted.
Either they corrode (if metal) or just plain break (if plastic). I did get one that was a pre-filled grinder that seems to have lasted the time it takes to empty it but of course you can't refill it (and it might well only last another 1 refill).
What am I looking for? What have you found that works?
Of course we now have masses of pepper grinders too!