Cassidy's Air Duct Cleaning And Air Sealing

We've hired this company several times to clean our ducts. They did do the cleaning quickly and the air smelled nice coming from the vents when they were finished.
We had a couple of vents where the airflow was much less than other vents in the house. Upon investigation the technician found lunchbags, pieces of 2x4 wood and crumpled cardboard shoved in the vents by the various contractors our home builder hired. I was disgusted by the behaviour of the tradesmen but nothing I can do about it so long after the fact. We still have some vents which seem clogged with stuff. Time to get them cleared.