Product review (5 stars): Works on the worst clog imaginable!
We just bought a home from an old lady who had lived here for 20 years.  I highly doubt she ever cleaned her dryer vent.  When we ran the dryer, the clothes weren't getting dry, and the entire mudroom was filling with steam.  The vent was so clogged that when I started to clean it out, I found that the steam had been trapped and had made the lint inside turn to mud.  I wasn't sure we could even take care of it ourselves.  But we ordered this brush to try or at least have it to clean inthe future.

I ended up being so extremely happy with this product.  It was flexible enough to fit around the elbow into the vent.  I attached one section to the brush at a time, twisted slowly, and then pulled it out to remove any lint that was dislodged so far.  Our vent was about 20 feet, so I wanted to make sure I didn't just push lint in farther and clog it worse.  With the first two lengths, I just twisted by hand.  After that, I used the drill, but I kept the speed quite slow, and I still continued to clear about a foot at a time and pull the brush out while twisting to remove what was dislodged so far.

The brush extensions seemed quite sturdy to me through this whole process.  I can see how some people broke theirs by running the drill too fast because if it caught on something while spinning that fast and with the force from the drill, even a very solid extension rod would break.  For example, once I got farther into the vent, it turns out there were PINE NEEDLES in the vent.  Once I felt resistance, I removed the brush, and a tangled web of pine needles started pulling out of the vent.  Apparently birds had been nesting in the vent!  No wonder there was a clothes line in the garage when we moved in.  The previous owner must have thought her dryer brokeand quit using it.  Then birds must have moved in to nest in the lint.  I guess it must have been nice for the birds until I moved in and tried to run laundry!  But if I had run the drill too fast, it would have caught in those pine needles and broken off for sure.

Anyways, I'd highly recommend this brush.  You can see the picture of the final amount of lint and pine needles that we pulled out of the vent.  It would have been so expensive to pay someone to clean that out.  This was so much cheaper.  I'll be using this every year, and I'll DEFINITELY be using it before I run a single load of laundry if I ever move again.