Monster Vac scrubs every duct. Vacuuming isn't enough. Monster Vac inserts a high pressure tool into each duct, to loosen dirt, and lift debris into the vacuum stream for removal. Your Monster Vac technician also has specialized brushes and air tools to clean any size or shape duct. He sends the tools traveling the full length of every duct to dislodge caked-on dirt.
Some companies only clean a few feet of each duct.
Some actually seal in the dirt you already have, so it stays forever. Monster Vac cleans your trunk lines, even if they're hidden in the walls. The trunk lines are the major arteries of your home's circulation system. They're where most of the dirt hides, and the trunk lines may be hidden in the ceiling or walls of your home. Most cleaning companies don't even have the tools to reach them.