Can you put pottery clay in oven?
If you put "real" clay (not playdough or modeling clay) in a microwave, you'll succeed in doing two things. One is heating it, and the other is driving moisture out of it. The latter is counterproductive, as the "correct" way to soften clay is to work moisture into it. Think this through and it will make sense. In a better equipped studio or ceramic shoppe, you'll find what is called a pugmill. This is used to mix materials like clay, and it is often used to "revive" material that has dried out a bit too much to be effectively worked. A sculptor or a helper can run clay and a bit of water through the pugmill and soften it. Anyone who has ever worked a bit of moisture into clay by hand to change its consistency knows how labor intensive it is. Roll up your sleeves if you don't have a machine. If you are seeking to soften oil- or polymer-based clays, warming them a bit will help, but note that the polymer clays can end up thermosetting if you are not careful. Clay made at home based in paper or flour is best softened in the manner of the clays used in ceramics -- mix in a littlewater with lots of elbow grease.