Thanks for forwarding citation. I agree this study says that 7% can be used therapeutically to kill MAC, but that 3% doesn't. . I will have to find the study my doc at UCLA referenced when my MAC was diagnosed in 2018, which said 3% was was as good--I think maybe the point of it (I cant remember) was whether 3% worked as well as mycolytic, thinning mucus (but not looking at whether saline was killing it). BTW, no doc has ever said anything about killing MAC with saline to me. After 15 years of totally dry cough, last spring I started having nagging productive cough instead of dry cough; in CT scan April 2020 some of mucus in little spots in middle lobe where I have bronchiectasis was gone, compared to some earlier scans. In 2018, I went to a doc who took the time to look at my CT scans from 2009-2018, and he said it waxed and waned over the years, would get better and worse. Im not sure if he meant the little spots of mucous were waxing and waning--