Pour Tajín or salt into a small, shallow dish in an even layer. Rub a pint or pilsner glass's rim with the cut side of the reserved juiced lime half, then dip glass into the dish to create a salt rim.
Set glass right side up and fill with lime juice, hot sauce, and Worcestershire sauce. Add a pinch or two of salt, fill glass with coconut water and top with beer. Stir gently if you want to mix it up a bit. Serve with remaining beer, topping up as you drink.