Product review (5 stars): My dryer vent is on the roof of my house ...
My dryer vent is on the roof of my house and has a few twists and turns to get there.  I hooked this up to my cordless drill (after taping the joints) and let it rip (with the dryer set on "air dry").  Here's a pro tip:  wear safety glasses and a dust mask as it was a snowstorm of lint!  This after having the dryer vent professionally cleaned about 2.25 years ago.

After completion of the vent line cleaning, I took the shop vac to the dryer itself.  Take the front panel off and get all the lint and dust out of there.  This removed even more dust and lint that is closer to the heat source.