I have been using one for years, an thought what is this doing for me? I felt no difference, my using it last about 10 minutes at the most. I read where others use theirs for 30 minutes 2 times a day. The stuff I put in it does not last long at all. I do not know if I am doing something wrong. So now I use a Acapella green, at least I cough up some mucus. Do not no if I should try the Lung Flute or the Aerobika? Love to hear what other think.