A:AnswerI do no think you are supposed to put the chocolate itself in the frother. However if you have powdered cocoa, you can heat up milk in the frother and add hot milk to a cup containing the powdered cocoa.
A:AnswerIt doesn't matter, the frother won't do anything if you're just heating up the milk, but there isn't a point in having it in there because you'll just have to wash that piece later anyway.