Some water softener salt is considered “food grade” - I don’t know which. But, if you sort that out, you can buy salt in #50 bags for a few bucks.
Halite is salt. Livestock salt blocks (not mineral blocks) are safe enough for human consumption. I'll eat them, even if I couldn't use them in a restaurant.
/johnny
Big no-no in the FDA manual, but I personally think it's better than the other nitrates for curing.
As a free man, I've decided that the benefit outweighs the potential downside. I don't need government telling me what I should consume within my own home.
/johnny