Product review (5 stars): Save yourself hundreds on a service call - buy 1-2 of these and run it through every year.
Work exactly as advertised.
Tip #1: definitely use this with a power drill/screwdriver, I couldn't imagine how difficult it would be to manually rotate the 'pipe' segments
Tip #2: You don't need to duck tape each segment together, not sure why they recommend that on the packaging - since the segments don't come loose unless you run your power drill/screwdriver in reverse.  I even had to use 2 pliers to disconnect the segments.