well that just isn't possible, your advice is mostly impractical in my situation.
what I can do is up the water changes in their existing tank and give some wundertonic, realising that the bug is in the tank forever until I take it down and bleach it, which isn't likely anytime soon because it's a beautiful and established tank. In reality probably all my fish will have been exposed to it because I don't have seperate tools for each tank. They probably carry all sorts of bugs and diseases that are waiting for an opportunity like every other animal.