That would definitely work, it's similar to how I do it. I don't have like the idea of having to control the temperature on the stove (I have quite an old stove with dialings 1, 2, 3, 4, 5 - 5 being the hottest setting so I have no idea how hot each can get to). I boil water in my jug and add it to a pot with 4 - 6 bottles then cover it with a towel to keep the steam in. Seems a bit primitive but it works fine, I let them sit for 10 - 15 minutes max and add some fresh boiling water at about 5 minutes. It works so well that I don't bother checking the temperature anymore, which is a bit foolish on my behalf.