there is a real low speed, fairly low torque pair of grinding tools in the ladies beauty section of Wal-Mart
they run on batteries, and are designed for grinding off foot calluses in one case, and fingernail/toenails in another instance
they make great little cheap paint stirrers, and low torque plastic grinders,,,,,,when removing plastic, if you get too fast with a steel bit in a "real tool",,,,,,you get melted plastic globs flying everywhere, or the tool sinks in and sticks to your work
Dremels are still useful, don't get me wrong,,,,,,,but, one of these cheapos can work for you, too
Rex