Just an hour ago I used a section of inner tube to open a resistant jar of strawberry preserves. I immediately thought of this forum but decided it was not worthy of posting. So I was delighted to find this thread resuscitated.
P. S. Do not attempt this with an inner tube still in the tire. You might get strawberry preserves in the tire. They would probably seal small punctures but cannot be depended on as sealant; besides, they are the wrong color.