@rebecross I hear you about nose vs lungs origin! My pulmonologist did not think I needed 7% either, thinking it was too harsh. Once I convinced him to let me have a trial, it made a world of difference. Nebbing 7% using the aerobika (flutter type device) inline with a nebulizer following by clearance autogenic drainage and huffing. It's not for the faint of heart! Time consuming and frustrating but necessary to keep me as well as possible (keeping yucky bugs at bay) and prevent daily coughing fits.