Air Duct Cleaners

I am told that “air-duct cleaning” is a waste of money, but what can I do to stop the continual mess?

thomas1981usa asked: The continual mess is that “soot” gets all over stuff in the rental property. You cannot feel it hit your face/body, nor can you see it. However, it makes everything in the place dirty. We have to clean quite often too. The problem has been better since we live here and change the [...]