Tr Trader Joe's employee discovered a live cockroach in a customer's shopping bag during a Reddit thread titled "Plz clear and clean ur reusable bags." The employee urged others to ensure their bags are clean and roach-free before bringing them into the store. While roaches may cause the disgust, others have reported instances of finding used needles, black mold, and even a dead rat in their bags. The best way to clean your bags depends on the materials they are made of. While many reusable grocery bags are machine-washable, others may need to be cleaned by hand, particularly if they are insulated or have cardboard components. The author also highlighted the need to consider the logistics of washing the bag before committing to a particular type.