Crayfish processing essentially involves harvesting them and storing them in fresh water until taken to market. As a result, market-form crayfish, which are commonly sold in breathable sacks, contain sediment and other debris that must be removed prior to preparing. Purging with fresh water serves as the ideal method for cleaning crayfish for cooking. It rinses organic matter and sediment from their shells, and, since they have no food supply when purging, evacuates their alimentary vein (intestinal tract).
Place the live crayfish in an insulated cooler with a spigot.
Cover the crayfish completely with cold water. Do not cover the cooler.
Drain and refresh the water every 15 minutes.
Continue soaking the crayfish and refreshing the water every 15 minutes until the water clears. Do not allow the crayfish soak in the water longer than 20 minutes before changing the water; the oxygen in the water depletes to dangerous levels after 20 minutes.