You could try Aiptasia X on them? It may have the same effect. The other technique is to inject lemon juice directly into the disc.
There are a couple of fish, Racoon butterfly and Bicolour Angel but no guarantee with them and not sure of their compatibility with your reef tank. Maybe a few peppermint shrimps could possibly eat the small ones.
Sorry fo being vague, only ever had an aiptasia prob before, but all worth a try if they are ruining your fun with this hobby.
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