Garage sales:
This varies from JW to JW and from congregation to congregation and region to region.
Only bizarre JWs in my area thought that demons were present in used clothing and other items at garage sales and thrift stores.
Many an elder's wife stopped at a garage sale duing field service on a Saturday. Other elders wives routinely went to garage sales every Friday. A pioneer sister told me about a CO stopping at a garage sale one Saturday.
I view any elders who told the rank and file not to buy things at garage sales were using it as another way to be the conscience of people in the congregation.
Blondie