Hey Kathy,
If you could point me in the direction of some data I'd appreciate it. I come from an empirical/clinical research background and have learned that experience is only valuable if it includes corrective feedback and an objective mind. Otherwise "experience" just means a person is repeating the same mistakes over and over. I'm always willing to learn something new, but I have difficulty believing that the marine biologists, aquarim curators, well known hobbyists that I've met and others are wrong just because someone says so. I'd like to see some proof to refute what I think I know. Not trying to be a pain in the @$$, like I said, I'm always willing to learn something new. I just want to see some current, objective information. I'm not using research and articles to support my opinion, I'm trying to use facts to determine my opinion.
Also, neither I nor others are claiming that the freshwater dip is a panacea. Rather I think that it eliminates enough of certain types parasites to allow the fish some breathing room. If the fish is relatively healthy it will then be able to fight off the parasitic infection itself (given the appropriate environment). I've used freshwater dips with tangs that were badly infested with Ich. A week later they were free of visible parasites and their behavior indicated a return to good health.