You'll get dif. opinions on that product but the majority will say it won't work. My dad's friend said it worked in his tank. Meanwhile, lots of others said they're tried it before and it didn't work. Im not really sure if it works or not as im a beginner also but the best way to treat ich is to QT the infected fishes then treat them with hypo or copper. Yes it sounds like alot of work setting up another tank just to treat diseases but that'll be the majority of the advices u'll get. Another way to treat ich, in which u won't have to take the fishes out, set up a new tank and other tidious stuff, is to combine lots of other weaker methods together but it's not 100% guaranteed that it's gonna work.
3 weaker methods that should use together:
1. Garlic soak fish food
2. Cleaner shrimp
3. Kick ich
Im sure there are more ways to combine with these 3 methods but those are the only 3 i could think of right now. Remember tho, the best way is still to QT the fishes and treat them with hypo or copper.