Regarding access, I get mine sent directly to me from the hospital pharmacy. I don't think my regular pharmacy would carry it.
As far as helping, I did notice a difference, however, it is harsh on the throat. Mucus comes up much easier. I wouldn't go back unless I had to.
Good luck finding it!

Directly from hospital pharmacy. I used it for the first year alternating with 7%. It takes a lot of getting used to. I did find it very helpful in -finally- being able to get mucous up. Now I just use 7%. I also use an Afflovest. I used it on medium for the first 3 months. I recently had a bad infection and changed the settings to high on percussion, vibration and drainage. Within a few weeks I noticed a big difference in the amount of sputum production. I also periodically use it while lying down and that seems to be helpful as well.