Sounds like snakeoil to me. I guess you know it's working if your fish don't get ich.
A healthy tank goes years without any ich. I think that's mostly a result of a clean, healthy, low-stress environment for the fish, and proper selection/ quarantining of fish. I don't think a bottle of anything can be a substitute for good husbandry, and if you practice good husbandry then you'd do better to use the $40 to buy them a couple movies that they might like to watch. It'll probably do more to make them happy and healthy.
There are a thousand "cure's in a bottle" at the LFS or online, and the easiest guidance for a new reefer is to add nothing except for fish food and a source of calcium and alkalinity to your tank. As you learn more about your tank you may decide on a couple other minor supplements, but just ignore all that stuff for a while.
