A user of a different stack exchange site recently mentioned a supposed polar bear killing technique devised by Inuit hunters. I found it quite difficult to find any other source for the story, but eventually managed to track down a reference to a book from 1919, Ethnography; a partial and preliminary description of the races of man by Loomis Havemeyer and Albert Galloway Keller, and turned up the following quote from page 151 of the original (or page 163 from this online copy):
In hunting the polar bear one method is to freeze a coiled spring made of bone into a piece of meat and leave it on the ice. The bear swallows it, the heat of the stomach melts the meat, the spring flies out and tears the stomach of the bear so that it dies shortly.
Engineering a reliable trap out of bone and raw meat and keeping it tightly compressed during freezing seems like quite a challenge, to say the least. But even aside from that, I'm not sure that the authors of the book could have seen such a thing first hand or even spoken to someone who'd done it themselves, and they didn't cite any sources.
Have there been any other plausible reports of this hunting technique?