Product review (5 stars): Easy to use, made a huge change in dryer usage
Followed instructions for use while dryer running, with one exception.  I didn't put in the dryer vent blocker, I just had someone inside to tell me when the brush was nearly to the dryer, (you can tell by feeling the flex tube).  Using this tool cut my dry time for clothes roughly in half.  I'm terribly happy I bought it, and I'm now loaning it out to my friends.