A Dremel is really too fast for that. The Dremel speed control may have a reversing switch; I don't have mine any more so I can't look.
A big problem with using a wire brush or any non-rigid tool to grind/polish is that you get cycloidal patterns in the work because the tool oscillates at the system's resonant frequency. Once the patterns start, changing the frequency won't even help. If you've tried to drill an unguided hole, even with a drill press, you've seen the problem. The hole is anything but round.
Great idea with the compound.
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Stupidity got us into this mess - why can't it get us out?
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