A photograph, not a promise
Ducts hide inside walls and floors, which is what makes this trade easy to fake: the customer cannot check the work. So the job here ends with showing you. Photos before the quote, so you know what is in there. Photos after the cleaning, so you see it gone.
What comes out is not subtle. In newer Omaha houses it is drywall dust, tape rolls, and scraps the builders dropped down the registers. In older ones it is decades of dust, webs, and now and then a nest in a cold air return. All of it shows up on camera, then leaves in the machine.
Notice what is not promised here. Nothing on this page says how your house will feel or smell afterward, because nobody can photograph air. The promise is the part you can see: clean metal, every run, on camera at your door.