Hello Anthony! This is not an irrelevant question. We certainly don't want you to go bald!
1) For this formula, you may use any type of cinchona (Peruvian bark).
2) Any brand of tequila is fine. I have found Jose Cuervo to be good.
3) Cover the infusion. When you make it, you can just keep it in the tequila bottle, covered and left to infuse for fifteen days. Don't forget the one small spoonful of salt.
Please let us know if this clarifies things!