@oram Welcome to Mayo Connect, and to our group. We have a wide variety of experiences with bronchectasis, MAC and other related infections.
Hmmm...I don't think any studies have shown that 7% saline can cure MAC. If you read them carefully, they say the MAC bacteria cannot survive in a 7% saline solution. Other Non-tubercular mycobacteria (NTM) are sensitive to other levels of saline.
NTM are very tenacious, but generally slow-growing bugs, and are all over our environment, so exposure to some is unavoidable unless we live in a sterile bubble. It is believed (though I don't know if it has been proven) that having a high level of saline suppresses growth of more bacteria by creating a less-welcoming environment. I don't think you could ever inhale enough saline, and deep enough, to reach every bit of lung tissue, so I doubt saline would ever cure MAC in the lungs.
That said, we neb 7% saline (or 3% if that's not tolerated) to keep our cough productive so we expel the mucus where MAC sets up its happy little colonies and grows them in our lungs. And we use our lung clearance devices or tachniques to help it along, as well as other meds like albuterol as prescribed.
Living with bronchiectasis and MAC, one uses every advantage to try to stay healthy and off the nasty meds required when infections worsen.
I saw in your first post that you have had blood in your sputum, and that the 7% saline didn't produce an immediate result for you. Have you been coached in other techniques to bring up sputum, like huff-coughing, a device, postural drainage or percussion? You can find lots of information about these here or on-line. Feel free to look around and come back to us with your questions.
Sue