Dehydration and electrolytes are but a fraction of what is truly driving a hangover. You can’t simply wash one away with water and salts.

The worst part of a hangover is when the liver is processing acetaldehyde. At best you can delay that process, spread it out, or shunt it to a rest period. The body still needs to process it.

https://www.mcgill.ca/oss/article/health/curing-hangover

Life saving info, only available in the US.