When I was on vacation this summer my spare time reading took me down a trail on this topic. If I have Ich in my system I want to treat it now as with changes I am planning over the next few years will make it much harder to treat later. The thought is that being sold in fresh water (but happy and even able to reproduce in full salt water) black mollies would never have been exposed to marine crypt so they would be succeptible, and being black it would easily show. I picked up a couple at a petsmart for a couple bucks and put them in a 5 gallon tank I had around. I acclimated to full salt water strength over about 5 weeks via small water changes, and used cheato after I got to 1.010 to help with water quality. I lost one about half way through the process, but the other is living in my 65 now where I see him picking at algae on the rocks. I am happy to report it is clean, but I do fear it doesn't know to avoid one of the 10 or so bubble tips in the tank, we will see!
Has anyone else tried this method?