I was surprised at how effectively the table salt DID work -- I just walked up the garden path sowing it like seed (and feeling like Odysseus trying to avoid being drafted to Troy). I guess once it's dissolved it doesn't really matter how big the grains are.

Did you see this one-- somewhere mid-story it says that Lanarkshire Council are looking into shipping in salt supplies from Africa:

http://news.bbc.co.uk/1/hi/scotland/8440213.stm