Understanding the life cycle of the Ich parasite goes a long way in getting rid of it. I tried Hypo but my PH was just way too hard to keep under control past 1.015. I've also tried Cuprimine, but never having used it before and not doing enough research, I didn't know you couldn't use Amquel with it, so I ended up killing my fish
I've got 2 new fish in QT and I'm doing the tank transfer method to be pro-active. Keep in mind that just because the Ich isn't visible doesn't necessarily mean the fish don't have it. From my understanding many times they're buried in the fishes gills etc and only when they enter a certain stage of their life cycle and when the fish's own immune system can no long fight them off are they noticeable. When they are no longer noticeable, chances are the cysts have fallen off the fish and are burying themselves in the substrate of the tank where they will soon burst forth again looking for a host. That is why I think the tank transfer method will work the best with the least impact on the fish in the long run. But, alas, you still need to run a fishless DT for 8-10 weeks to starve out anything in there that remains in the substrate.