Well, if you say so. I am assuming, by the way, that you are referring to (monogenetic) gill or skin flukes, which are the only kind that can really persist in an aquarium (unless, for some inexplicable reason, you are also keeping freshwater mussels in with your discus). And that you and your experts are diagnosing this based upon an actual observation of the parasite itself, and not just on some behavioral analysis.
Having said that, I do not believe that salt will be effective in treating this infestation. It is not on the short list of recommended treatments, and in addition has the disadvantage of raising the TDS (total dissolved solids) in the tank, something to which discus are particularly sensitive.
The recommendation is for a standard anti-ich remedy with a formalin base. The most effective of these treatments that I have ever used is Quick Cure, which is a malachite green/formalin combo. The life cycle of flukes is about 15 days at maximum, so I would treat for the full period just in case one part of the life cycle is more susceptible to treatment than the others (as it is with ich). Just before your daily treatment, do a 40-50% water change to keep ammonia and nitrites low, as this medicine does inhibit biological filtration to a certain extent. Also, large scale water changes are another recommended method of treating flukes, so you get two treatments for the price of one, really. And, of course, make sure that you have removed the carbon from your filtration system and that the filter is reasonably clear of organic detritus as well.
Raising the temperature in the tank will also help make your discus feel more comfortable. You don't need to go to extremes in this (especially if you are leaving the keyhole cichlids in there during all this), but something in the mid to upper 80's would be desirable.
Any help will be appreicated, thank you!
