Yes, there was an article on this, where the salt was used to weather an aircraft. I can't remember the issue exactly, but swanny's site explains it perfectly, and if you still have problems with it, you can allways ask someone here.
It's a great (read: cheap and easy) technique to use. I've tried it a couple of times. It's good because the paint actually looks like it was chipped, but I found that controlling where I wanted the salt and didn't took a little bit of patience..