Product review (4 stars): Ok for short vents
This actually did a great job of getting out the lint.  However, once I turned my dryer on...I realized that I had also blocked the vent.
I sent my husband under the crawl space and he then found out that the vent was about 30 feet long, turning this way and that.
So the 12 feet of linteater only touched the outer part.

My husband decided to blast it from from the inside out, with the electric blower.  This sent out a huge amount of lint to the outside.

I wonder if just doing that would have done the trick.  And saved me some money?

Anyway, for short vents the linteater would be great.