I approach it slightly differently. I heat my lead in my pourer and don't use a pot and ladel. I pre-heat my moulds with a quick wave of the oxy but you can do this in the oven also. After the first pour it isn't really necessary after that. Once the lead is moulten and flows around easily its ready to pour. Once its poured you only have to leave it for 30 seconds or so before you crack open the moulds. Don't worry about throwing it in water as it isn't required and if there is any water in the mould when you pour the next time it could blow back in your face. That's the way I do it anyway. Plenty of ways to skin a cat. One thing I will say is that welding gloves, safety glasses and a face mask or respirator of some sort are essential.
Cheers, Clutter
Cheer