In a large pot, combine the garlic, celery, jalapenos, onions, 1 tablespoon of the seafood seasoning and 10 cups of water. Bring to a boil. Add the potatoes and reduce to a rapid simmer. Cook until the potatoes are almost tender, about 10 minutes.
Add the sausage and corn to the pot. Cook until the potatoes and corn are cooked through, 5 to 7 minutes. Stir in the shrimp and cook until the shrimp are opaque throughout, about 1 1/2 minutes. Reserve 1 cup of the cooking liquid. Drain the shrimp mixture and return it to the pot. Add the butter, hot sauce, parsley, the remaining 1 tablespoon seafood seasoning and the reserved cooking liquid and toss to combine. Serve with more seafood seasoning.