Personally, I don't believe you can ever get all the order out. Leave the kilt in a warm car for a little while and the heat will release the order even if you think it is clean. The owner will spend the life of the kilt trying to cover the odor. Someone who is de-sensitized to smoke may not notice the odor if it is weak but someone who is never around smoke will pick it up immediately. Cigarette smoke just has one of those strong, distinct odors that is virtually impossible to get rid of.