I know you explicitly said not to do this on the comments but I don't really feel like writing a whole post of debunk ideas and uninspired and half-hearted posts are a no-no. A little respect for the readers, right?

As for ideas, I'm totally getting them out of my granny's and other old folk's reccommendations over the years:

1. Don't eat and bath/get into the pool/get into the sea etc or you can have an embolism. This one I actually more-or-less cleared a few years ago, but it would still be interesting to read about.
2. Don't drink coffee (or other hot beverages) and then a cold one or you can basically die out of the temperature difference. The cold-first-hot-after order is allright, though.
3. One glass of beer after exercise helps recover fluids and lost electrolites (okay, not an advice from my grandmother, but from my beer-loving sports buddies. We never stop at only one glass, though).
   4.Oysters and such are aphrodisiacs. It's a must in my country to see vendors on the beach shouting 'vuelve a la vida' ,' rompecolchón' (meaning 'come back to life' and 'matress breaker') while trying to sell you surprisingly non-fresh looking oysters and clams out of a mayonese jar, claiming they will revitalize your sex life. Never tried, but I can't help but wonder.

Those are the ones that come to my mind, I hope you find at least one of them interesting enough to write about.

Happy debunking!