When I was stationed at Ft. Bliss Tx there was a "cure" mentioned for a hangover, menudo. It's a soup made from tripe (beef stomachs), hominy and chili. I never had the guts to try it. I tend to shy away from eating internal organs because of the ick factor.
I haven't used this for a hangover, but it is my sick tummy favorite soup, sort of based on a Chickasaw recipe:
1 lb ground meat (pork's best)
2 regular sized cans of hominy, and their liquid
1/2 bag frozen bird's eye pepper stir fry vegetables (this is the one with just bell peppers and onions)
3 cans chicken broth
ground black pepper
Paprika
(you use 2 or three times more paprika than black pepper, probably at least half a teaspoon.)
Fry and drain the meat, add the peppers, and when they are about done, add broth, hominy and liquid, and spices.
I have made it with hominy grits when I didn't have the canned hominy.
Simple soup, very easy on a sicky tummy, and probably very nice on a bad hangover. Haven't had one of those since about 1990. Never ever ever intend to get that sick again by my own hand!