Everyone has their own "home remedy" for ich is seems. I think in the end after you battle it a few times you just do what is right for your own tank. I know this does not say much, and perhaps I am just talking in circles
All I ever do to treat ich is soak my food in garlic before I feed, I also tend to feed a little bit more during an ich outbreak as well. I find that by keeping any added stress to a minimum, they tend to get over it within a week.
I hold true to the theory that ich is always present in our tanks. My two tangs just started getting some ich spots yesterday for no good reason. Nothing new has been added to my tank so it was not introduced from the outside.
Now by many other peoples experience here I am a newbie, only having kept salt water tanks for 2-1/2 years but in that time I have battled ich more times than I can count and I have yet to lose a fish to it.
*knock on wood* maybe just dumb luck, but I really tink people overcomplicate when it comes to ich treatment.