In a large bowl, soak the chopped conch meat in water and juice from half the lime for about 10 minutes. Rinse off and drain.

Place the conch on a flat surface and pound with a meat tenderizer until about 1 inch thick. Cut into smaller chunks.

In a food processor (or finely chop by hand), combine conch, celery, onion, garlic, scotch bonnet pepper (if using), juice from the remaining half lime, salt, and black pepper. Blend until well mixed.

In a large mixing bowl, whisk together the flour, egg, and milk until smooth. Stir in cayenne pepper to taste.

Add the blended conch mixture into the bowl with the batter and stir until fully incorporated. If using pepper sauce, add it now. Let the batter rest while heating the oil.

Heat oil in a deep pot or skillet to 350°F (175°C). Using a spoon or small scoop, drop spoonfuls of batter into the hot oil. Do not overcrowd the pot.

Fry the fritters, spooning hot oil over them as they cook, until golden brown and cooked through—about 3 to 5 minutes per batch.

Remove fritters from the oil and place them on a paper towel or brown paper bag to absorb excess oil.

Combine equal parts ketchup and mayonnaise in a small bowl.

Add pepper sauce to taste and stir until smooth. Serve with hot fritters.