Product review (4 stars): Does the job well - but make sure you have shop vac
Used it once (I also bought the extension rods as my vent system is a bit long).  You will need an available shop vac to place at one end so as you clean from the outside-in, the lint gets sucked into the shop vac.

Doing it slowly and carefully had great results.  Opening the shop vac revealed quite a bit of lint.  I will use it regularly now to keep the vent clean.

Tip: do tape the connections. Go slow, back and forth with each added rod.  And ALWAYS GO CLOCKWISE whether cleaning or retrieving the rods out. Save your shipment box to store the extra pieces.