Yesterday I bought a kit for cleaning my dryer vent..... I had been using a vacuum cleaner but it wasn't doing as good of a job as I wanted and the vent clogged anyway. The one withe the brush and long push rod similar to a fiberglass cable snake. Well it went OK and got the job done but was a little more aggravating than what I wanted. Having some 1/8 inch SS cable around I fabricated a pull rope to be left in the duct. A test cleaning showed I could pull the brush from end to end in about the time it takes to think about it. If you decide to try this make 2 pull ropes...pull one in when you pull the other out.
Jimmie