I usually put some ‘dry’ pots on top of the kiln when it’s firing. It’s a way of making sure that all of the physical water id driven off and I don’t blow up any pots inside the kiln. Water, in the kiln, turns to steam and steam expands. That’s what powers a steam locomotive! When the steam expands and cannot escape through the wall of a pot…BOOM! It blows up. The first 400 degrees of temperature rise in the kiln is the critical part. You can also see that I’m drying out some scrap clay that I will recycle. Why let all of the residual heat from the kiln go to waste when you can use it for other purposes besides firing? One warning: if you place some pots on top of the kiln, put them around the edges of the lid where it is supported by the kiln wall directly beneath the weight of the pots. Never place anything in the middle where there is no support for the lid!