Pour 3/4 cup boiling water over the dried hibiscus flowers or Red Zinger tea bags and let steep at least 5 minutes.
Fill a pitcher with ice, 1/2 cup cooled tea, tequila, lime juice and Triple Sec.
(Smaller amounts can be made in a cocktail shaker — two drinks at a time.)
If desired, salt the glasses by rubbing each rim with a lime wedge and dipping into a plate of kosher salt.
Pour into glasses filled with ice or serve straight up.