I've seen some streamers do what they call "hand and brain", meaning that one person plays while the other chooses the kind of piece that they must move. All cases I've seen were intended for having fun. But it got me thinking about how effective would this be as a teaching tool.
My question, at heart, is: "Is playing hand and brain with a student an effective teaching tool?" Since this is probably too opinion-based, I only ask if there are cases of GM's/notable coaches that employ it as a teaching tool consistently. If there are references attesting to it being an effective teaching tool, those are of course appreciated.