When I was carrying my mono galliera, I would wipe it with a damp cloth every couple days. And believe it or not, dirt (or dust?) would come off. I did this very lightly. Is it weird to "baby" a bag in such a way? My Artsy MM will be here in less than 48 hours and I don't know if I should do the wiping down thing. My bags are on my shoulder and passenger seat in car so I don't know where the dirt/dust is coming from.