This is most likely a reference to this /int/ post. A Vietnamese anon said that he used the skull of an American soldier to eat rice in special occasions

I wonder if it is some cultural thing, on short notice it's usually the Vietnamese or some minor Asia nation with people toying around skull bowls.

>documentary on life in Vietnam after the war
>what delicacies people enjoy even in relative/extreme poverty like laying rat traps in rice fields and eat them
>reporter looks for snake wine
>elder brother goes on a mystical rant on how the snake will make you strong
>younger brother goes on the scientific merit and assures the concoction is technically safe to drink
>both produce skull bowls and offer one to the guest