How about you circle the guy at a mile final. A go around on the side of the runway seems dangerous to me. You still have 2 within the runway environment pointed at each other. Too many things could go wrong. What if they guy you try to send around loses their radio, or more realistically just doesn't hear you. Now you have two rolling down the same runway opposite direction at each other.

Two facilities ago I worked at a place where there was a lot of this going on. I just circled them at a mile final and sequenced them in to the runway in use. If they declined the circling maneuver then they were instructed to leave the pattern and were not allowed any more practice approaches. Was pretty simple in my eyes. You either go the same way as everybody else or go bye bye. It was consistently enough traffic where you couldn't really accommodate opposite direction all the time, even for practice instruments. We even had 3 parallels and still had to circle or deny.

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