The oven IS a good way to sterilize larger amounts of soil, tho. I use turkey roasting pans when I want to do a bunch at once.....but only if I'm not planning on eating anything very soon!
I've read that you do need to keep an eye on the temperature of the soil. It needs to be HELD at around 180 for half an hour. (Get out the old meat thermometer!) Apparently you can cook it TOO long and it does nasty things to the soil. Can make it toxic to plants, somehow. And you do need to make sure it's moist when you start. About the level of moisture you'd use if planting seeds in it.
