Low temperature will kill them, and is less likely to damage fabric. If you have a deep freeze (❄️❄️❄️ -18°C, not just an ice box) that should do the trick. A few days below -6°C is supposed to be fatal, but I'd give them a week at -18°C to be absolutely sure.
Low temperature will kill them, and is less likely to damage fabric. If you have a deep freeze (❄️❄️❄️ -18°C, not just an ice box) that should do the trick. A few days below -6°C is supposed to be fatal, but I'd give them a week at -18°C to be absolutely sure.