Lol, this thread reminds me of the Beatle's movie "Help!" in the scene; "The Exciting Adventure of Paul on the Floor". I can picture a hungry Bearded Dragon chasing down the shrunken Paul for dinner.
However on a serious note, although I don't keep any lizards and therefore can't know for sure, I have seen Christmas Beetle shells in wild Water Dragon poop so I am guessing they would be fine....