Using liquid nitrogen for tenderizing octopus?
The most delicious octopus I've ever eaten was tenderized by freezing first for a couple of days and then letting it sit at room temperature for a couple of days.  Then it was baked with onion, salt and coconut cream.  The smell while it was baking was unbelievably ... organic?  Okay, it smelled like boiling jockstraps.  I think it wouldn't work for people with delicate stomachs, but for people who still have the gut flora to handle naturally macerated meats, the octopus was soft and tender and the flavor was incredible.