While freezing one's kilts has been mentioned, what if you don't have enough space in your freezer?

Well, I just ran across a related alternative I'd never heard of before: cryofumigation. Seal your kilts or other items in plastic bags containing dry ice (frozen carbon dioxide) for 3-5 days. The garments are thus bathed in carbon dioxide gas, denied oxygen, and it kills moths at all stages from egg to adult.