Product review (5 stars): follow instructions closely
I called a company and they wanted $200.00 to clean my 'dryer duct'.  So I went to Amazon site, and found a 'great' recommendation for this product!  Used it and retrieved about 4 cups out of the 'dryer duct'.  I don't have a drill, so I did have to turn it 'my hand' to the right as instructed, so the sections would not come loose!  A little hard for a senior lady to do it!  But, it worked, and I saved $180.00