As for Supernatural, I'm honestly not sure. I think it was more of a "throw-way" plot, since they never really brought it up again. But I would imagine it'd kill both the host and the demon possessing it.

Out of all HP films, I've never seen OOTP on-screen. I refused to, since it dealt with the death of my favourite character. My friend's trying to drag me to HBP, so I guess, we'll see. (I'm feeling very 'meh' towards the movies lately.)