Well, it's spray foam insulation that someone sprayed into a large chinese bowl. I did, however, figure out that if I got a small chisel and was careful (!), I could, and did, remove all the spray foam from the large bowl. What fun! I was hoping that there might be an easier way, but no. First, I took a sharp knife and scored the whole thing, then used a metal spoon to pop it out. Finally, I used the chisel to get it off the sides and clean it out. Now, I can see all the little goldfish that were painted on the inside of the pot.
Thanks, everyone, for your ideas! The husband one probably wouldn't work. He's down in Palm Springs dove hunting. yum!