It’s "scam"
Infiltrates all groups / Facebook / nextdoor.
Similar to car detailing
The business is interesting, the people offering the service are often not local and just generate leads . Once there is a commitment for the work, they subcontract to someone else.
So it’s not really a scam but really misleading advertising at best. Clearly the market of people having central air with air duct to clean on Garfield place is not significant.
I think the google group only has one admin and access appears to be public, thus why we had 2-3 emails of the sort lately.