This is kind of why I haven't replied directly to this one yet. I don't know how I feel, ethically, about wasting interviewers time. I've been on the hiring side of the table a ton in the last 13 years (just not on the other side of the table) and I'm not sureI'd be trilled if I found out candidates were doing this to me.
With that said, ethics aside, it does seem like a solid way to get practice.