Give 'em the ol' freshwater dip. I did that with a Regal tang, and it worked... it was a very minor case though. All you have to do is put fresh, not salted, dechlorinated water into a small bucket or so, and put the fish in there for 3-5 minutes. The fish will look disoriented, and will act differently, but don't worry. He wont die. When you look at the clock it seems as though time is going by very slowly haha. Try that and see what happens.....

unfortunatly I dont think this will take the ICK out of the aquarium water, but then again, I don't know too much about it.