I did some digging. There is an actual hangover remedy based on this simple soup. It involves adding one extra ingredient: just a pinch of baking soda (like maybe 0.5g of it). Apparently this turns an already good electrolyte balancer into magic.

As I said I have never had a hangover so I can't attest to that, but someone I know who does get hung over knew about this soup and about this specific alteration. He said it doesn't change the flavour noticeably but it settles the stomach like nobody's business.