Never mind (unless you have something to add). Just found this online:
Preparation:
Thoroughly wash the crawfish in a large "foot tub' by rinsing and draining twice, until rinse water is reasonably clean. Cover crawfish in tub again with water, and add 1/2 pound of salt (the salt is added to purge and clean the crawfish prior to eating). Stir for no longer than 3 minutes, and drain water. Immediately fill the tub again with cool water, leaving out the salt, and stir for 3 minutes, then drain (if the crawfish are allowed to soak in the water too long, they will die). Inspect and discard dead crawfish, bait and other debris that may be present. For a 40 lb sack of crawfish, fill an 18-20 gallon pot with about 10 gallons of water (or enough water to cover crawfish and vegetables when they are put in). Bring to a boil.
Cooking:
Add cayenne pepper and crawfish boil seasoning. Bring mixture to a boil. In the basket (that fits into the pot), place bay leaves, potatoes, lemons, onions, mushrooms, and garlic. Place the basket in the boiling water, and boil these vegetables and seasonings for 10-15 minutes, stirring occasionally.
Carefully add live crawfish into the basket, which is already in the pot of boiling water. Stir, cover, and bring back to a boil. Remove cover and let the whole thing boil for 4 minutes. Remove entire pot (with basket in it) from heat (or turn of heat), add corn, stir, and keep covered for 5-20 minutes. The longer the crawfish are left to stand like this (in excess of 5 minutes), the more seasoned and spicy they will be. You also want to cook them long enough to release them from their shell to make eating them easier.
Start sampling (tasting) the crawfish after 5 minutes (of standing) to achieve the desired taste and consistency. Personally, we
recommend that you let the crawfish stand covered until they begin to sink, which means they are thoroughly marinated with
the water and seasonings, which is somewhere around 15-20 minutes. They should be quite spicy by that time, so be careful.
How to Peel Crayfish
1. Grab the tip of the head and the tip of the tail; twist in opposite directions. Discard the head.
2. Grab the tip of the tail; twist the top part of the tail.
3. Pinch the bottom part of the tail; take the meat out. Remove the black vein on top of the tail and discard. The meat is now ready for consumption.
