Product review (5 stars): The right tool for the job!
This kit is exactly the right tool to clean properly configured dryer vents, and it works.  Simply attach it to your drill and start collecting the lint.  Works great on hard pipe.  Does fine with flexible pipe if you can stretch it out straight.  It probably will not turn more than 90 degrees, so if you are using flex like that, you may have to disconnect it to get it cleaned out, otherwise you will risk damaging the pipe, particularly paper, foil, and plastic flexible pipe.