I was wondering if anyone in here has used any of those outfits that
clean your air vent/air duct cleaners who brings a big truck with a
pop up roof?

I've been calling around for estimates and information and from what I
gather there are those who use a hose to send down your hot air vents
and cold air returns to blow with compressed down to your mainlines to
which the vacuum hose would be attached and suck out the dust.

Another type, supposedly more thorough cleaning, is first sending down
a rotating brush down the hot air vents, then use the hose with the
compressed air. I was told that they don't brush the cold air returns
because sometimes there are electrical wires and cables running
through them.

Do these types of duct cleaners really work to reduce your household
dust and would the brush method be that much cleaner? The places I've
called are all registered with the local BBB and have good records.

Thoughts? Thanks for your time and courtesy.