Clean crawfish: put them in a large bowl with running water pouring over the top. Swish and allow the mud to clear, with the water still running. Remove and rinse with running water over a colander. Discard any crawfish that are dead.
Fill a large stock pot with enough water to cover all the crawfish. Add in the all the ingredients except for the basil and crawfish. Bring to a boil, and let boil for 10 minutes.
Add in the basil and crawfish. Cover. When the water begins to rapidly boil again, cook for 1 minute, then remove from the heat. Let the crawfish sit in the boiling liquid for 10 minutes to cook through.