I had these guys in my tank too. I had a nice piece of red monti growing off a piece of LR that I had to pretty much destroy breaking off to get it out of my DT. You'll need to remove ALL your monti caps out of this tank if you really want to get rid of these guys...pretty much have to starve any survivors. Be careful removing the pieces not to blow any nudi's off. Then, you'll have to scrub or even remove any infested areas with Revive (I'm pretty sure it's Revive?). Anyways, if you feel or are unsure that you might not have removed all these pests and their eggs (which are almost impossible to see) off the infected pieces, then I'd toss them.
It's not worth putting them back into your DT. I scrubbed mine down, trimmed off any really bad areas that were suspicious and put the left over piece(s) into my QT tank. That was about 3 months ago. It's been growing in there just fine w/o any issue. I could put that piece back into my DT now if I wanted to.
Always keep a good eye on these pieces in your DT. I hope my story helped. Good luck.