How to bake Plasticine clay?

I made a few charms out of Plasticine modeling clay and I'd like to bake them. However, there are no baking instructions on the package and it says that the clay never dries out. Is there any way to bake the clay?

If you expose it to heat, it'll just melt. That kind of clay is a combination of oils and waxes and is formulated not to harden no matter what you do to it.