Oh ye of little faith, who wanted me to throw out a great pot.
I can report that the pot is clean. Actually, it's cleaner than we started.
I'll explain what we did.
After the initial meltage plus scraping off whatever we could, we put the pot on high heat on the stove top and that may have gotten rid of a little more plastic. Then I tossed it in the barbecue with live coals in it. There was a bit of a burning plastic aroma. I scrubbed and the pot was smooth inside but stained.
I then talked to my Dad on the phone and he suggested a little bleach. I did as told, putting about 1/4 inch of bleach inside the pot. I left it, uncovered, in the basement slop sink so as to not have to smell the lovely aroma of Clorox. Two hours later, I went downstairs to get the pot and noticed the bottom was cream-colored. It had not been cream-colored since we had purchased the pot, back in 1990 or so.
There was an aroma of bleach so we hand-washed it out, then ran it through the dishwasher twice. It was probably fine after the first run-through but I wanted to be certain that the smell and chemicals were gone.
We've used it twice and we ain't dead.
PS This pot is part of a set that we bought with money from my bridal shower. How could I throw it away?