Product review (5 stars): Fire Hazard gone, easy to use, no drill needed
Even with a few bends in my ducts, this product worked great. Because of the bends, I found the drill awkward - it probably works better on vents that don't need as many poles attached together. However, I found that I really didn't even need the drill. I was able to push it from the inside to the outside, where 8 years worth of lint fell out, and my dryer is working efficiently, and my firefighter husband is happy to have prevented a fire hazard.
For peace of mind, I ran the brush through (inside to out) 3 times until the amount of lint that came out was just dust. I did tape the poles, as instructed, but they seemed very secure without the tape, so without the drill, I completely trust it to get the job done well.