I think i may do this. Makes sense and will be drug free.
From the article
. The problem is, moving a fish from an infected tank to a clean tank is a proven cure. It is one of the variations on the daily water change method that I mentioned in my first article on Cryptocaryon irritans (Colorni, 1987). In that paper, Colorni describes moving an infected fish between two tanks. The tanks are cleaned and dried between uses, thereby ridding them of tomonts. He instructs to do this every three days for ten days. This is very similar to what happened with the Purple Tang. There should have been two more moves, but Cratylus got lucky with just the one.