About a year ago I noticed an infestation on my zoas. I started dipping and then manual removal with a turkey baster but they just kept coming back
Then I added a leopard wrasse and have not seen a nudi ever since. He cruises the zoa gardens and picks off pods and nudis without discrimination. Other small wrasses that are know to eat nudis are canary wrasses, Melanarus wrasses, fairy wrasses (solarensis), six line wrasse (although I would personally not recommend them to anyone).