Confused, I was. So I Wikipedia'ed the hell out of the subject. It seems the term 'kosher salt' is used more or less exclusively in the USA to refer to coarse-grained sea-salt, because it can draw more blood out of meat than common-or-garden salt. (Might write a book sometime about a Jewish vampire). So the kosherosity or not is a complete misnomer.
Here's the recipe, obviously by someone who has never been close to the real thing.