The very best ways to prevent ICH in the aquarium is by use of a quarantine tank for new fish before they go in your main tank or display tank and,,by maintaining the water quality in your tank. Weekly water changes,not over feeding, and not over stocking.
As for medications, I haven't tried the product you mentioned but it is always best to follow the directions exactly, as to doses and length of time for medicating. Also a good idea to not use the nets or other tools used in sick tank on main tank and vice-versa.
I have used product Quick Cure which is found at many fish stores and walmart. It contains formalin and malachite green. If directions ar followed, it works well for ICH.
I and many others, use a small quarantine or hospital tank say,, ten gal. They are cheap and it is much easier and cheaper to medicate and perform water changes in a ten gal. than a larger tank.