Earlier quoted context omitted.
Out of interest, why do you prefer a salt grinder? I've never understood why these exist. Pepper grinders, absolutely - the aromatics are released on grinding. By not so with salt. Curious if I'm missing something.
Grinder means finer salt. Finer salt sticks to things better (you can get a baby powder consistency). And the way the salt "tastes" is different because the powder dissolves on your tongue differently/quicker. Salt "dust" is a really interesting way of adding salt to food -- and you actually end up adding less than larger grains
I've never seen on-the-spot ground salt smaller than the stuff you can buy already grounded. Except if you buy flakes, but then why do so if you want finer salt?