Hi I also combine saline nebbing with my smart vest session and have an easier time producing sputum this way vs nebbing first & then the vest. My doctors approved. It doesn't work for everyone which makes me wonder if it has something to with what areas of the lungs are affected (mine is in both lower lobes which makes it harder to expel mucus). There are quite a few of us here who have success with the vest, you just don't hear about it as much since folks are more likely to be posting here with requests for help solving problems. And it's a great helpful bunch of folks! So I hope the combo works for you.