Product review (5 stars): Actualy works as advertised!!
Very few products work as well as they do in the advertisement.  I was really surprised by this product.

I have a dryer vent pipe that is about 30 feet of 4 inch schedule 20 PVC running through the slab foundation.  It cleaned an amazing amount of lint out of the vent pipe.

The only thing negative I can say about it is that you can't buy replacement parts individually.  If I ever wear out the little brush, I will have to buy a whole new kit.