Some of you guys who've traveled to Alaska have probably heard of this.
Friend of mine, chopper pilot who did 2 tours in 'Nam, just went and he did the challenge. It was a hoot hearing him tell about it. He's grumpy old guy, just what you'd expect from a guy who's seen what he seen. He shocked everyone in his group by doing it.

http://www.atlasobscura.com/places/sourtoe-cocktail