Product review (5 stars): Simple and effective! No need to call a professional!
This was so easy to use! I'm no handyman by any stretch of the imagination and even I was able to use this with success. You simply attach the tubes to your drill (start with 1-2 of the 4 2' tubes before using the rest of them), only drilling clockwise whether pushing it in or pulling it out, and push it with the drill through your dryer vent and it brushes the lint off all around the inside. I did it from the roof outside and placed a garbage can under the inside dryer vent.

The tubes are very flexible and can handle 90 degree turns.