Good idea for sure... I've used the drill setup to start my engines in testing before but with the higher compression modified engines I've also stripped out the nut that holds the magneto magnet down so I use wider nuts on the magneto now to prevent that problem again... With the stock nut, it stripped the nut and the threads on the shaft, just a word of caution there, but it works.
the idea of using a squirrel cage type fan is also a good one so you can run longer without the worry of overheating