Product review (5 stars): Does the job.
This did an incredible job cleaning out my PVC pipe that runs through the foundation out the back of the house.  Only problem was it wasn't long enough, (my run of pipe was about 25ft.  I just had to run it from both sides and that fixed it up.  I used a leaf blower sealed with duct tape on the inside of the house to blow while I was running it and this was quite effective.

Drier works like new now.