Results are mixed, and therefore I don't have confidence in it. The only true guarenteed way is copper (or ttm but that is stressful and a pita).
There are other "reef safe" options like kick ich and rally pro (I don't see how kick ich would do anything based off of the ingredients) that some people have tried and claimed that they worked, but its not a reliable yes and therefore casts doubt on how accurately these people are able to tell (not just the results, but the disease itself). I would resort to one of the reef safe options if you absolutely can't set up a QT.
Back drop, bad ich outbreak, lost a bunch of fish, learned to quarantine, display went fallow 80+ days, everyone great whole time in observation tank until display was ready, once back in display BAM! ich showing up on Powder Brown Tang. Tank is Cade 1800 running dual uv, 55watt pentair and 40...