Your best bet will be a Halichoeres. I had some absolutely nasty flatworms. If I recall, Salty did mention that the Black Leopard they have is a great eater when it comes to pests. I personally don’t know if my blue star is eating pests as I have so far been lucky as to not see any in my nano. I know for a fact my chloropterus loved hunting the flatties. Later I tested with nudi’s and both my iridis and chloropterus went after them (Yes, I willingly put Nudi’s into my display tank).
I have found that one half of Halichoeres prefers the worms and the other half prefers the “bugs”. Whilst some are inbetween and don’t really care. For example, I have found that Leucoxanthus doesn’t really care what pest it is. Same thing with Chloropterus and Iridis.