That's why I only put red wigglers in my hospital tank for whomever I have in there (right now my 3toed I rescued sick) to hunt once they start feeling better (which is one method I use to gauge when whomever is starting to feel better). But I never put anything with teeth or pincers or such.
I like roaches too. Roaches won't harm or bother a living animal and they are a great food source for any insectivore.