Product review (5 stars): Great product
I was skeptical.  Bought it on Amazon.  Used it for the first time yesterday - it's amazing how much lint came out of my 10-foot duct.  Enough to fill a 5-gallon bucket.

Easy to use, only took about 15-20 minutes, including cleanup.  My duct is super clean now.  I had NO problems.  Would recommend to others.