I gave this a try the other day.
I was cutting an inlay of my daughter's name for the lid of a trinkit box, I was left with a piece of wood with the letters cut out of it. then I rememberd this thread, went to wolly world (walmart) and bought some of this clay. mashed it into the letters and cooked it. I found it actaully expanded slightly after baking.
I think it was surprisingly easy to use, sanded easy and worked well with a polycrylic clear coat.
Thanks for making this post, I can see lots of uses for this.
Mike