Just remember the visible signs of ich will clear up on its own in 8-10 days (roughly) if the fish continue eating. This can give you a false sense of success with treatment products. Because the parasite would have gone away anyway.
I just got thru a nasty bout of ich by feeding heavily. I did lose 2 fish, but 5 others that had it bad are now 100% cleared up.
From my experience, It may show up again when the cycle is complete but if my fish are strong and unstressed, it will be mild and easily fought off. After that, If my fish continue in good health, it wont show up again. Tho I also know it will always remain in the system unless I go fallow.
I tried kich-ich many years ago and it did nothing but stress corals, some of which never recovered.