Product review (5 stars): Did a great job.
I had a long, bending duct to clean out and with the help of a power drill, it was easy.  By hand I could only get the brush to go in for three sections, but once I used the drill, I was able to get all sections to easily go in.  As per the directions, I inserted one section, attached the next and secured it with a small piece of duct tape, and once I couldn't move it forward by hand I attached the drill.  As I drilled in each section, I would take the drill off, attached and secure the next section and continue.  Afterwards, I took out the entire length and disassembled the sections, wiped them off, and stored them away.  I hope I'll only have to do this once in a blue moon, but I'm sure this kit will be up to the task of many more cleanings.