To clean, spread crayfish out on the counter and remove any dead ones. Put the rest in a colander and spray with cold water to remove any sand or silt.
To remove the crayfish’s sand vein, boil briefly. When cool enough to handle, turn the crayfish stomach up, firmly grasp and twist the tail until it cracks, then gently pull out the vein.
To boil live crayfish, fill a large pan with water and flavorings (herbs, spices, and vegetables, such as carrot, onion, and celery), and bring to a rapid boil. A few at a time, plunge crayfish into boiling water. Reduce heat and simmer until the tail meat is opaque, about six to seven minutes. Serve crayfish in their broth.
To eat crayfish, pinch the sides of the tail until you hear them crunch, pull away the shell, and pick out the meat. For small crayfish, twist off the head and suck the meat out of the shell.