BloodyBaroness
Captain Titsworth
It is used for dogs, cats, and if I'm not mistaken, avians.
Again, it's all about the dosage and how diluted a shake you give.
I think that's the big point. It is used a dewormer in very very young kittens and puppies. Dosage and dilution are the key.
In the wild reptiles ingest all kinds of bits, shards, flakes, and general crap, I think they can handle some DE in a slurry. You gauge the dosage by the size of the animal, and not daily. Their kidneys will be fine.