How do mints work?

[Kartowl]

I red the description but I cant use it on any of my pokemon.

[Enzo]

Hello,

Nature herbs can only be used on Suicune, Shaymin and Unown.

It doesn't work on any other pokemon and you have to breed the pokemon by having it hold an everstone in order to keep that nature.

I hope this clears up the confusion!