Bring a grill-safe pan to temperature and place the clams in the pan. Add the bloody mary mix to the pan with the clams. Add the fresh thyme, oregano, hot sauce, Worcestershire, horseradish, red onion, garlic, celery salt, Old Bay and allow them to steam lid down for 3 minutes.
Open the dome and move the ingredients to one side, then add the mussels to the pan. Close the dome and bake for another 5 minutes.
Season the sliced baguette with a touch of Old Bay and toast off.
Squeeze the lemon juice over the top of the open shellfish. Garnish with the thinly sliced celery.
Take the pan off the grill and add the vodka. Stir to fully incorporate. Serve immediately with the grilled crostini and enjoy!