Product review (5 stars): Cleaned a 24 foot drier vent run!
We purchased two of these kits to clean a 24 foot drier vent run that is in our house slab.  We pulled out a huge pile of soggy drier lint.  Just guessing but I'd say we must have been 80% or more blocked.  This duct cleaning kit(s) worked great with my old trusty electric drill.  Just take your time, when you feel it hit resistance, push it forward a bit then drag it back to remove the lint, then feed it back in.  No problem working the 24 ft of tubing.  Probably saved us from having a drier fire!  I recommend this product.