There is a problem with this method. Ich serves as a 'contaminant' and therefore can be introduced in the tank via unquarantined fish. Most people have a misconception that ich is part of the tank's ecosystem. Doing this method may remove the ich from the fish's body but they are not completely removed from your tank at all. Once your fish has ich in the main tank, you'll need to treat the whole tank, not isolate the afflicted fish. The same goes with external parasites like fish lice, fish leech and anchorworms. Treat the whole tank. The possibility that some of them exist in the main tank is already there because they fall to the bottom where they lay eggs and the larva will be released and search for new hosts.
I had posted this one in the other forum regarding ich and if it may benefit you, then I'm glad it helps.
your right but i keep discus in that tank now and the water is always 88 degres so i dont know if there is any more ick in there or not havent seen it in years