from my expirience any fish i ever gave a fwd in has not lived too long aftert that.
can't you just set up a 10 gallon as needed for a hospital tank with a coppersafe in it?
since i have done that every fish has lived and has been cured.
bump up your cleaner shrimp army also
your dip tank should be 80 per cent fresh and 20 per cent tank water. Than raise the ph so its the same as your aquarium water the temp needs to match also. Put the fish in slow and watch respiration if it gets erratic put back it in the aquarium some fish will lye on ther side this is ok. a 5 min dip is best but no longer than ten min