The sure way is BURN IT
Or Hire a cleaning crew, made service, whatever. Get a garden sprayer
and 10- 30 gallons of bleach, yes , cheap bleach. Spray the basement
walls with a 50% mix . Wash Floors with 15% mix Wash walls with
??? 15% mix . Stay at a hotel 2 nights, Laundry whites w/ bleach,
Leave vent fans on . Retest. But one BIG problem , Your Panic..
I s it a bad form of mold, there are 1100 known so far, and only a
few are toxic. Unless you and your family are health affected by the
house or the drywall removal it may not be a problem, unless its
defined as a " bad mold" stachybotris or other. It is passable .
Mold is everywhere in life , its on you too. But I understand your
concern. Id spray and vacate for a few days. Is it a new purchase,
Because your furnace ducts are a concern, so is a better furnace
filter. Dont get upset talk to your city or doctor , you dont want
to panic , but you need information as to ' The Mold " what it is
and how it will affect you