Kosher salt - I never heard of that.

do they ritually kill the sodium or the chlorine?

Its not a bad idea, snorting stuff to clean out the sinuses. I don't think I'd trust myself to get the quatities or the concentration right. Supposing you sniffed the wrong way and got brain damage. Do they make a propietary brand to do that with.

My father used to use TCP. But then again - he did many strange things in the bathroom.