This illustration depicts Yu (in white flowing robe) trying to civilize the barbarian chief (in leopard skin) over a cup of wine. It is true that the "barbarians" already possessed ceramic utensil at the time, and they might even greet guests with liquid drinks instead of chunks of meat, though unlikely. Still, Yu's priceless robe was awesome! Came without weapons or bodyguards, Yu was exercising his skill of persuasion to gain allegiance from a fierce warrior. I find such stories incredible, but judging from many people's respect for Yu, I think others actually believe in them.
Picture source: Wang Shu-rong, ed, Illustrated stories from Shi Ji, 21th-Century Pub House, Nanchang, 1990.