I wanted to add that I tried the way Dr. Warwick described doing the Vest in Amy's blog. It could be a coincidence, I'm not sure but, ever since I have been easily coughing up quarter size blobs of gunk at night. I don't recall ever doing this before and it's been great. I cough once or twice in the middle of the night and up pops a big blob, without any effort. I can't help but think this might be b/c of the way I'm doing the vest now, that it's losening up stuff from deep within and I'm able to get it out during the vest treatment and well after.
Dr. Warwick's way is basically opposite then the way the doctors have always told me to do it. His theory makes you reduce the pressure while increasing the frequency (speed), and his way does not force you to go to pressure 10 if it's not right for you. Usually doctors have told me to go with the highest speed that you can and as tight a pressure as you can handle, and go for 30 minutes. I figure since Dr. Warwick was the one who invented the Vest -- I'd give his suggestions a try!! I'm liking it so far.