Bring a large pot of water to a boil. Add bouquet garni, crab boil, lemons and garlic. Add the largest of the crabs first adding the remainder of the crabs and removing the crabs as they become cooked.
In a sauce pan, melt 1/4 cup of butter with a few peeled garlic cloves. Simmer the butter for 3 to 4 minutes to infuse the garlic into the butter. Remove from the heat and discard the garlic cloves. Serve immediately as a dipping sauce.
Place the crabs on a platter and arrange the sauces around the platter.