The OP states:
"What concerns me more is does it come from a drunk-free, drug-free home. I think befuddled owners are far more worrisome than pets or children."
One persons Bottle of Wine is another's Oblivion and there are Plenty of Prescribed Drugs that are to be taken very regularly, which are able to do a much better Job than occasional used Self Medicated Drugs.
Is Audio Equipment bought from an individual partial to a Bottle of Wine and on Prescribed Drugs an OK to purchase from Vendor or Not ?
Or is the prejudice restricted to individuals that are Vendors with what could be diagnosed as a progressive problem with Alcohol, who are prone to use Self Medicated Drugs as well ?
Which person should make known their Mental State / Dependency towards such substances in their Sales Ad ?
Kid Free, Pet Free, Smoke Free home could mean the items are offered for sale from a non Smoking individual who is recently estranged, now living alone in accommodation where there is no room for the Audio System and it is better of sold to pay the upcoming cost of Dissolution and Alimony.
Is that personal situation also something that should be made known in the Sale Ad.
Alternatively, how about the anti-thesis for the sales ad. My shiny Tonearm with a $5k Cart' attached is a magnet to my Five Year Old Grandchild, I've had to stop them grabbing hold of it on more than one occasion, it is frustration when they knock the Cart's Stylus Guard Off, I think I have been lucky, hence I'm selling the Cart' just in case the worse happens at another time.
Is that personal situation also something that should be made known in the Sale Ad.
What ever the Sales Description and the aside information added, it is the Purchaser who needs Caveat Emptor as their best guidance through the inquiries being made and possibility of a Purchase.
My Pet Hate is Vendors, which are met occasionally that try and Bully the Sale Through. Where their response to an inquiry is seen to be the reason for the sale to be Closed-Won with immediacy. These types of individual, Do Get the Middle Digit and achieve a Closed-Lost for their input.