It's tough getting a little guy out of reef to medicate and QT. I could never rearrange all of my hard work for the sake of it. I know I am stating the obvious (And I think it was mentioned prior), but hyposalinity is not a good idea for obvious reasons. Inverts don't like the SG
drop below 1.019. I have never put much faith in chemical cures advertised to get rid of ich in a reef tank simply because anything that is not strong enough to kill inverts, is probably not strong enough to erradicate the parasite.
If I were in the same predicament, I would do water changes every couple days for the next couple weeks--say 1/3 of the volume. I would also improve surface agitation with an extra power head. I used to get garlic extract at the lfs
(A little pricey) and soak a frozen cube in it for a couple minutes prior to feeding--I believe that this keeps the desire to eat on point and I feel that it is important for the immunity and slime coat of the fish. Many people would disagree and state garlic as just a homeopathic mythical hobby remedy. Last but not least, I would say a prayer every night before bed. Hope it works out for your little guys there.
As a side note, the best I have ever done to stop an outbreak was to keep the other inhabitants that were healthy, in tact. I usually lost the fish that showed the signs initially, no matter how hard I tried with increased tank maintenance.