I’m not sure about salt, but my mom puts red wine in it. 0/10 not recommended.
A tiny bit of salt is actually pretty damn nice in coffee! And I mean a small sprinkle on an entire pot
Some people put butter in their coffee.
Wouldn’t surprise me. I used to know a girl who put black pepper in her milk.
Putting salt in coffee is relatively common. Put a very small sprinkle in shitty coffee and it makes it a lot more tolerable. Think bad waiting room coffee etc.