Product review (5 stars): Awesome!
This thing is awesome!  My neighbor was concerned about his dryer vent being partially plugged.  Since my daughter had been having troubles with this same issue, I purchased this and cleaned them both.  This thing literally had the inside of the pipe shiny after using it with a cordless drill for just a few minutes.

Highly reccomend this product.  The instructions tell you to put tape on the connections so they don't come loose, but if you just keep your drill turning to the right you'll not have a problem with this and can skip taping the connections.