@SnIPpY I wouldn't use it. They will probably eat it and they will get dehydrated which could cause serious health problems.Hi Miss Lydia
Grit salt is simply very coarse salt that is not yet refined. Otherwise I should be able to use normal salt as well and simply mix it with the soil/sand on which they sleep. I will get a small sample of the salt first and see what they do with it, but any advice will help