I have heard fresh garlic oil from garlic cloves works best. If you crush the garlic clove your supposed to get some liquid out of it. Thats what your looking for. You can also find garlic oil in your grocery store. Try to find pure garlic oil and not a bottle with extra stuff in it.
Soak the food, flake or frozen in the garlic oil. Then serve it up to the fish.
Probably the best bet is to put a little garlic oil in a small bowl. Put some flakes in and let it soak for 10min. Then take the flakes out and feed them.
Continue normal maintance procedures....
Once you have gotten rid of the ICH its important to try to figure out what the source was. What was causing stress on the fish to the point that they surcame to the ICH parasite.
Good luck.
Oh and remember a succesful reefer once said...
"...nothing good happens in a reef tank quickly take your time and you will be successful..."