Only table salt, and probably popcorn salt (which is very fine) contain the anti caking ingredient. Larger courser grains of salt, like kosher, do not need it. But there's really nothing wrong with grinding up kosher salt to avoid the anti caking ingredient. But I wouldn't pay a premium price for a fancy set up.

I piss off people when I challenge them after they say "plain vanilla". I don't care, I will continue to do so.