So the boiling method worked. I stuck the collar in a pot, covered with water, added a dash of liquid detergent, and let it bubble for about 15 minutes.
The gum disappeared entirely, disolving, I guess. And the pan survived unscathed as well. Also, the cleanest part of the collar is now the little circle where the gum was. It’s a bright and cheery spot, while the rest is a comfortable, lived-in shade of green. Guess we discovered a whole new way to do laundry!
Thanks, B5!
Magrilless 
he he
Dad told me the dog/collar/gum story on the way home from San Antonio airport last Wednesday night. He started the story with the circumstances first..a dog collar with gum. Now this is a perfect example of how Dad and I think differently. I immediately thought of using acetone as a solvent…it certainly would work, is fast and has a great smell. But on the other hand is not as safe and environmentally friendly as Dad’s boiling method.I like mine better: more complicated and involves chemicals. he he he