Make the aioli:

Place the garlic and salt in a mortar large enough to hold all the ingredients, and pound it to a smooth paste. Add the egg yolks and beat with the pestle until well combined.

Begin adding the oil, a few drops at a time, letting it run down the side of the mortar, beating continually until the mixture starts to thicken. The aioli mixture should begin to thicken immediately. Continue adding all the remaining oil slowly in a steady stream, always adding to the side of the mortar. If the ailoi becomes to thick to beat, add a few drops of Meyer lemon juice to thin it out. Then stir in the remaining Meyer lemon juice. Cover and refrigerate until ready to serve.

Prepare the crabs:

Wash the crabs under cold running water. Bring a large stockpot (at least 12 quarts) of water to a boil. Add the salt and 2 to 3 crabs. Return the water to a rapid boil, cover, and boil the crabs for 12 minutes. To test doneness, pull off a leg—the meat should be firm and white.

Using tongs, remove the crabs from the boiling water, and rinse under cold water. Bring the water back to a boil and cook the remaining crabs in batches.

To clean the crabs, remove the top shell and then the gills on either side of the body. Rinse under cold running water. Turn the crabs over and remove the triangular piece off the breast body. Cut the crabs in half and tear off the legs.

Place the crab pieces onto a large platter. If not serving immediately, cover the crab, and refrigerate. Serve chilled with the garlic aioli.