Using a magnetic stirrer will mix the juices so that there is no hot spots in the juice, also there is less air getting mixed in to the juice so your nic will degrade a bit slower.
Best way to steep is let it sit like a good old wine in a dark place for a long time.
Ok i just went and watch the episode. I personally feel that the guys that are steeling there the recipes must be named so that we a community can actively boycott them