One of my skunk cleaners almost stressed a BTA to death by constantly yanking food out of it's tentacles. It would wait for me to feed the nem and I'd have to shoo it away with a turkey baster! I've never seen a shrimp munch on coral though, that's a new one.
The cleaners are more daring asking for food than my dogs. Same story, I'd spot feed and the thing would just zoom around the syringe playing bongos on whatever I was feeding. My partner originally told me that she thought she saw it eating my hammer and I thought she was crazy... A few weeks later I caught it red handed. Unfortunately I didn't have anywhere for it to go so it decimated my hammer and a torch, but it has since been rehomed and I see new heads forming on both. Minor setback, and lesson learned.