Hello Helen, I had a cavity about 2 years ago. Once it was diagnosed I stopped using the nebulizer and started only using dry salt inhaler with 99% pure sodium chloride and also an infra red concentration on my lungs with the wand. When I went to the Mayo in Rochester to begin preparation for an up coming VAT procedure to remove the cavity, the CT scan indicated that the cavity had collapsed and no surgery needed. I did share with my doctor what I had done but since it is outside of the framework of medicine he thought it was interesting but anecdotal. I have a minor degree in TCM and felt that inhaling cold, wet into my lungs was not the right thing for me and the cavity. That's why I changed tack. Here is a link to PUBMed about new research on MAC. It is very in-depth and full of medical speak. You may find it interesting. https://pmc.ncbi.nlm.nih.gov/articles/PMC7862709/#s7
The prevalence of MAC infection is growing world wide and the research continues. Hope this helps.