I had a student who had crafted a vase which when turned upside down was
properly configured for a bong. I noticed he would turn it over and show
it off when he thought I was not looking.
It made it through the bisque fire, and was even glazed. When it came out
of the kiln, however, all of the orifices had been sealed with clay (it
just fired into the glaze). I watched him turn it over and wonder, but he
could not complain. I guess I had the last "word" no matter how silent.