Wild caught clowns, with maroons in particular seem to get afflicted with this most. My GB maroon had it and I successfully got it with a FW dip, but I think I was lucky, if not coincidental. As said, be sure none of the other fish are showing any symptoms, such as excessicve mucous production, listlessness, or lethargy.
If you have removed the higher life from the tank- ie- fish corals, crabs, etc., you can turn up the heater to the low to mid 80's. This will accelerate the"incubation" and metabolism of the bacteria, protozoans, pathogens, etc, and will run it's course a bit faster. Make sure there is nothing that will be negatively impacted by higher temps.