I saw something a couple days ago that made me remember this thread. I was in pet food express, petsmart, or petco. One of the big petstores, I'll have to take another look around, I think it was Express. It was liquid calcium, intended to be mixed into the water. I looked online later and found a bunch that were sprayed onto the food before feeding. I know the drinking water one might work for something that drinks water normally, but amphibians absorb water through the skin, so I'm not sure it'd work well, if it'd even be absorbed, etc.