You can use Apitasia X. It will kill them. If you get them all they might not come back. The trick is to get them all. You will need to keep at them because they get where you can not see them. Scraping them off just makes for little pieces and they will spread. Peppermint shrimp will eat all the mid size and little new ones.
Filefish, Cleaned my infested 180 gal tank in about two months. I have had him in my tank for about a year and a half now. one of those he's so ugly he's cute fish.