I can't recommend any (personal experience-wise) as I always QT'd any infected fish out of the main tank to treat them. But hopefully someone else will post up with suggestions.
There is anecdotal evidence that feeding garlic extract may help the fish fight off the infection, however this his highly dependent on the species involved and the level of infestation. Quite frankly most have success with hardy fish that stand a good chance of fighting off the parasite anyway.
Removal and treatment of infected fish may become necessary.
Quarantine your fish in the future to prevent this problem.