I had these guys about a yearago. Took piece by piece out. Finilly when I had a hand full left I took them out. It's not worth trying to save things. The problem is was soon as the hit ur system they start searching for new sources of food. Monti's, digi's anything in the familly. I even seen one on one of my deepwater acro. But it wasn't eating it. They move quick, one night I did the flash light test and seen a MENudi on the glass it moved 10" in 7 min. So they can get around.
As for time needed to make sure they r gone out of ur system. All the data i've read says no less then 6 months with out a food source but 9 months is best. I went 6 months and was fine.