Does anybody know where you can buy rock salt? I know it is used in the making of homemade icecream, but I want to use it to bake potatoes. Red Lobster uses it to do their baked potatoes and they are yummy. I have looked on the internet and found out how to do it and all about it except where you can buy it. I have been using coarse sea salt and it is working (for two potatoes) but would like to do a large number and this is gourmet stuff is rather costly. The potatoes go on a bed of rock salt and are to be fully covered. Any help would be appreciated.