Unless there is an anomaly (stain, particularly long walk on a hot day, etc.), I wear my wool pants 2 days in the same week (I travel 4 days, bring 2 pair), one week per month. I then air them out, and have them dry-cleaned quarterly (give or take). I also own a wirlpool fabric freshener which I use occasionally if I went someplace smoky, or want to get out some wrinkles from travel w/out pressing. I VERY rarely wash my denim. Again, natural fabric benefits much from plain old fresh air, unless you are greasy or spill stuff on it.