My fear of them is playing a big part here guys. Yes I'm afraid of them, I'm afraid of spiders too what's more is how big they can/do get. I don't want a 20" worm in my tank. I'm afraid to put my hand in my tank the minute I put any food in there day or night they just come crawling out from everywhere. If I spot feed my LPS they'll crawl right on top of em and take the food. I actually watched a worm play tug of war with my peppermint shrimp over a piece of food!
Best way to slow them down in my experience has been starvation.Reduced feeding and when you do feed use a nylon hose or net to suspend the food and very low No3 will slow em down along with good flow to help export detrus.Coris wrasse is a sure way also as stated.When in controled numbers they are good for the tank tho.I zapped one with Mike Z's zapper man was he un happy ( RIP ) Good luck