Product review (5 stars): worked like a charm
After noticing that my gas dryer wasn't getting too hot anymore I figured I would have to pay someone to clean my dryer vent.  My laundry room is in the middle of my two story house and the dryer vent run to the outside of the house is probably 25-30 feet.  I saw this item mentioned in an internet article and after reading the reviews I decided to give it a try.  Since my run was so long, I started cleaning from the outside adding one section at a time and emptying my shop vac as needed.  One thing to keep in mind is that small shop vacs do not work well for this and easily clog.  The instructions mention this but that is all I had.  It is best to use a large one with the wider diameter hose.  I added all four sections (securing the joints with duct tape just in case) and ran it in and out multiple times from both the inside of the house and the outside.  What came out was shocking - the lint compressed from being in my vacuum could fill up a plastic grocery shopping sack.  After completing the cleaning I would say that my dryer runs about twice as hot and drying times are cut in half.  Great product at a great price!