Didn't read all the responses so I apologize if this has been mentioned but if you're doing the demo-
PLEASE WEAR AN APPROPRIATE RESPIRATOR AND GOGGLES.
In a house of that age, you're going to be stiring up dust and chemicals that are insanely destructive to your neurological and respiratory systems.
Is also recommend an air scrubber but at a minimum, tent off the room with poly.
A easy tip for setting up containment is say you're working in 1 room....
You'll need:
Roll of 4 mil poly
Can of spray adhesive
Roll of blue painters tape
Zip walls ( cones in a box of two for $18.97) at HD.
Cut a piece of poly wide enough to cover the door plus a few inches.
Put blue tape on the door frame.
Use some spay adhesive on the blue tape.
Wait about 10-20 seconds and then put the poly on the door opening.
Put the zip wall on and you're done.
Good luck