There's currently a thread ("I want to be trained" by eraser) near the top of the Knowledge Base section that should give you a good idea of what some of us think of that idea.

In brief, my vote was for Dom/mes to be trained by subs and subs to be trained by Dom/mes. I think your idea (or being trained by a switch, which would be similar) is a very good one, for the reasons given by two or three people in the previously mentioned thread.