I've heard that garlic-soaked food can help treat ick. For this reason, I soak food a couple times a week in a garlic juice formula as a "pretreatment."
Apparently the fish excrete the garlic through their skin and the parasites can't stand the garlic. Either way, the fish love garlic....it has convinced my picky, stressed flasher/fairy wrasses to eat when they were first introduced to the aquarium. After a good feeding they settled down quickly and relaxed in their new environment.
Jodi