Product review (5 stars): Great Product - Gardus Lint Eater System
I was skeptical about the product but willing to give it a try.  I am glad that I did.  With the shop-vac connected, it collected a very large amount of lint and other items.  My dryer vents above the garage so there is about 30 feet of vent and I don't believe there is another product like this that would clean the entire path.  There was a lot of work in getting to the entire length of vent but it was well worth it.  Dryer now takes about 45 minutes instead of 90 minutes to dry heavy loads.  This is a quality product and worth the price and effort.