I carefully air out my sleeping bag in the sun after I use it and it is still fairly new. I don't feel like it needs washing, but around the area (10"x3"?) where my neck and chin make contact I see just a little grime that has collected.
I was wondering if anybody had a recommendation for spot cleaning a small area like that. It is on the inside, not the pertex outside fabric. I was thinking of a dilute hand soap on a washcloth, but I would appreciate any suggestions.