Fill a small bowl with about 1/2 cup of sea salt. Run a lime wedge around the rim of your glasses and dip it into the bowl, making sure the rim has a nice even coating of sea salt.
In a highball glass or jarrito filled with 1/2 cup of ice, mix together the pineapple juice, grapefruit juice, lime juice, tequila, mezcal and pinch of salt.
Give it a stir, then top off with grapefruit soda.
Garnish with orange and lime slices.