I don't know anything, but I've learnt what PCF means.

I have given up giving my Whites Tree Frogs full alive Earthworms because they kept crawling back out of the frogs mouths. I too experienced a very bad smell. & like your title I thort they weren't digested properly. But I've given cut up worms & I've not had any problems. I went the local fishing shop & bought a pair of scissors with 4 blades. For perch fishing aparantly the scissors were. Similar to herb scissors.