Place the shrimp in a large glass or ceramic bowl and toss with the salt and Tabasco. In a small glass bowl, combine the rum, lime juice, Worcestershire, and cumin. Whisk together and pour the mixture over the shrimp. Toss the shrimp to coat them evenly, cover the bowl and refrigerate for at least 1 hour and preferably 2.

Preheat a grill or broiler to high heat. In a small saucepan heat the butter and olive oil over low heat. When the mixture is hot and foamy, add the garlic and stir for 1 or 2 minutes, until the aroma of the garlic is released. Do not allow the garlic to burn. Remove 2 tablespoons of the marinade from the shrimp dish and add to the garlic mixture. Bring to a simmer and cook for 1 minute. Remove the shrimp from the marinade with a slotted spoon and discard the remaining marinade. Place the shrimp in a shallow ovenproof dish that will hold them all in one layer. Or, make a single layer of shrimp in the base of individual gratin dishes. Pour an equal amount of the garlic mixture over each, and sprinkle with the salt, pepper, and bread crumbs. Broil the shrimp about 4 inches from the heat source until golden and bubbling, about 8 minutes. Remove from the oven and let cool for 5 minutes, then squeeze a little lime juice over each and sprinkle with the parsley