I've had a NC28 setup for going on 2-yrs. Been through ALL kinds of CUC including all kinds of crabs, shrimp, snails, and fish.
In my experience, the most effective CUC is a nice heard of various sized nassarius snails (I have about 15) to keep your sand clean and eat up extra food. For glass and rocks, I go with either a few mexican turbos (I have 5) or 6-8 turban snails. Only catch with turbo's is they get big really fast and will knock things over in the tank if your rocks aren't glued or your corals aren't encrusted. Later on it doesn't matter much.
No need for anything else honestly. Hermits are effective, but at the expense of being "opportunistic" feeders like any other crab. I've also had emerald's that were effective, but again the same caveat.
Shrimp don't clean much IMO, I have had coral banded, scarlet's, fireshrimp, and peps and while I like having them all in the tank I don't feel they are "worthy" members of a CUC, just fun to look at.
Fish add bioload, and most good cleaners are not great lookers, so not worth it.