Product review (2 stars): Not worth the money
Ok, I guess this product makes sense in theory.  But it's definitely not worth the price they're charging.  There's really not much to it - a few extension rods, a brush, and and adapter (that didn't actually fit my vent).  And it definitely did not bend around corners in the vent pipe, so it could only be inserted part-way.  It seems like you could rig something about as effective without spending the money.