I have a zebra and a snowflake and I have many small hermits, small snails, a couple choc chip stars, some brittle stars, a knobby star, a few conch, and sea urchins. Also have a few mushroom coral and anemone. My other aggressive fish in the tank don't mind them too much overall. My big choc chip star had it's chocolate chips eaten off by my striped dogface puffer, but he stopped bothering it over time. Must not have liked the taste in the end. I was also cautious initially, but was glad to find that I could have a CUC with the aggressive tank...
I wish I could try cleaner shrimp, but I'm certain they would disappear in a few seconds.