There really is no full-proof way of treating an animal without subjecting it to proper qt procedures. Remember, disease and parasites are tough lil buggers and not always eliminated the first time around so you must be patient, yet persistent. Granted hyposalinity has its positives, but it also has a major negative which is allowing a broader and more aggressive range of disease and parasites to infect your fish...Ich is usually the last thing I worry about since it is usually so easily treatable, but in your case re-qt is the correct approach without cutting corners.
*Microb-Lift is just an immune system enhancer, much like garlic. You can try it, but I wouldn't place any bets and especially if using garlic is much more inexpensive.