It smells sorta sour like dirty laundry if that makes sense? When they lived here, you could smell their room from the opposite end of the apartment if they opened their door for more than 10 seconds. It’s definitely not that strong anymore but it still reeks if you’re inside or standing in the doorway and we’d really like to be able to use the room without dealing with their leftover stench. It’s been airing out (windows open with screens) for weeks now. Does anyone have any recommendations?

Edit: Additional information

The room has wood floors and drywall in some places and something harder in other places (uncertain, it’s an old building). They supposedly cleaned before they left, including scrubbing the walls with something (they didn’t tell us what they used) and we used our normal floor cleaner after they left.