What is the categorical difference between an ice cream stain and cigarette smoke? Because I honestly don't understand what distinction you're trying to make.
One is a physical stain that might very well be permanent. The other is an odor that will come out after literally one wash (or after airing it out for a while).
The ice cream stain might not be permanent, and the cigarette smell might be, all depending on the specifics, so I see no qualitative difference between the two.
