Product review (5 stars): Great value for the money
My brother let me try his set and I didn't want to give it back so I had to buy my own set! Great value for the money.  Works well, cleans great, just followed the directions and my dryer hose and exhaust were clean. It's amazing how much stuff comes out of the hose after a year!  You can use a corded or cordless drill. I used a cordless and adjusted the torque so I don't damage the hose if the brush binds on the hose, but it never did.  Remember to only use it in the forward direction because if you use reverse, the rods will unscrew themselves and be left behind in the duct. I marked the dates that I last cleaned the ducts so that I know about when my next cleaning is due.  I use the dates to remind me to drain the water heater as well to clear sediments at the bottom of the tank.