Product review (5 stars): Works great
Found this after dryer overheated and had to replace a fuse in it. Clothes were taking forever to dry and laundry room felt like a sauna. My vent is 10 feet long with a 90 degree elbow coming out of slab into  90 degree coming out of laundry room wall. I worked from outside and followed instructions, always having drill turn clockwise. Plunged each 3 ft section and added a section and withdrew after each plunge. Toward the end of the run i felt some resistance and withdrew some wet lint. After making sure i had gone end to end, I went inside and placed a 165 moh blower in the. I was surprised at the wet glob of lint that blew out. It filled a plastic trash bag and i am certain that my vent was at least 75% occluded. Clothes dry in half the time now and my laundry room is as comfortable as other rooms in the house. I like others taped each joint and plunged slowly and let the drill motor turn slow. Dont force it and you will be o.k.  Best money ive spent in a long time.