crudibility
What Pig Pen would lose if he removed his famous layer of dirt.
When Pig Pen says he's gonna take a bath when he gets home, Charlie Brown asks him if he's gonna get all cleaned up; said muddy child responds dat as soiled as he always seems to get, he's learned not to expect too much from a soap-and-water session --- "l just feel satisfied if da wash merely settles da dust." So it sounds like his crudibility will be preserved for da time being.