If you want to try and save the frag, you can try mixing up a slurry of kalk paste (add just enough water to the powder to make a slurry), put the frag in a separate container of water with no flow, and then baste the clove polyps with the slurry and let it sit for maybe 30mins to an hour.
I did this recently on a couple rocks with just a few clove polyps and so far they seem to be gone, but I'm still gonna keep a close eye on those spots for the next few months just to make sure. One of those spots did have zoas, and as long as not all the zoas get covered that should recover.
If it was a cheap frag and you don't want to run the risk, then tossing it might be the best solution.
I'm also testing overdosing iodine on a couple rocks that are absolutely covered, but I'm still too early in that process to tell if it'll be effective.