I'm looking into getting a clay saucer for my 18.5 wsm to keep the heat up during the cold months. I'm just not sure how they're being utilized. Do you foil it and put it in the water pan or do you take the water pan out and use the clay in its place? Seems from what I've read, a 14.25 in clay saucer is the prefered size. Any help would be appreciated. Pics would be great also.