When we had our ducts cleaned, the technicians first walked through the house and asked a few questions about the HVAC system and whether we'd noticed any specific problems. After that, they explained what they were going to do before bringing in their equipment. They covered the nearby areas to keep things clean and worked through each vent methodically. I remember being surprised that the appointment took longer than I expected, but they didn't seem rushed, which gave me confidence. They also showed us some of the dust that had been removed and recommended changing the furnace filter afterward. We noticed less dust settling on furniture over the following weeks, so overall it turned out to be a worthwhile experience for our home.