10 minutes is way too short, unless it's a rat pinky or something really small. I soak in very warm water (but that you're still able to run your hand in without getting burned) for an hour or a few hours, depending on the size of the rat. You don't want to risk a bit of the inside of the rat still being frozen, as it could cause necrosis and then death of the snake... Better to over-wait than to be hasty about it.