A bit late, and not answering your question (alas, I know nothing of what you seek), but it's worth noting that ORS includes potassium. Less important in cramps - from memory that's more likely sodium than potassium - but for the runs (even if short of cholera-scale) or a hangover, it's an important component.

If it is just the sodium you need, as many have pointed out, there's plenty of ways to get that other than sports drinks. Cheese is often pretty salty and mythically gives you fun dreams (fsvo fun) if eaten just before bed. Or a nightly tequila shot or two perhaps?