"I don't want no potatoes." indicates disgust. An example of the application of such a statement may be when I see they are prepared by being mashed, having a HUGE amount of salted margerine added, having too much 2% MF milk added, and then being whipped with a blender. Note that the statement I would like to use in such a case does not convey my actual feelings but "I don't want no fuckin margerine and milk in me spuds." just doesn't seem fitting nor polite at a Kissmeass dinner to which I have been invited.