Old wives tales they call them. Received wisdom that underpins some natural remedy or non-medically approved treatment. Or some secret that circulates among certain groups who not at the forefront of society.
When to eat pineapple has an old wives tale associated with it - that spans multiple cultures.
Except Romania, where they don't have pineapples, so make do with onions instead.
It's all true that feedback from customers. You can learn a lot about people from the ingredients in their sandwich. That should be a tee-shirt slogan.
I think it was cucumbers too!
Onions are great in sandwiches. Not as much in tea 😁