@cwal I own an Afflovest, which I found effective for loosening phlegm. It worked best when I used it during nebulizing (ombra compressor with inline aerobika and sprint nebulizer). Before committing, I trialed Afflovest vest for 2 weeks and the Hill-Rom vest for 6 weeks. I much preferred the Afflovest because of its effectiveness and that it was not tethered like Hill-Rom's. That's the good part of my experience.

The bad is that after a month of using it I developed rib pain on one side. Perhaps I'm uneven and my rib cage sticks out more on that side where I got the pain. That's what I'm guessing. I experienced shooting pains on one side, not during its use but randomly as I was out and about. Once I stopped using Afflovest the pains went away. Recently I tried it again, sadly same outcome. Your results might vary! Definitely ask for a trial, longer the better.