Bama, here's a recipe for preparing them the traditional Finnish way:
30 crayfish (live)
1 gallon water
10 sugar cubes
½ cup seasalt
loads of crown dill
Boil the water, add sugar, salt and dill. One by one, drop the live crayfish in the water. Once it starts boiling again, boil for 8-12 minutes. After they've been boiled, remove them from the stock, chill the stock, and place the crayfish in another container, add more fresh dill, pour the stock on top. Store in a cool place and enjoy them the next day.
Ok, I'm way behind, but in La. we do 40lbs at a time. Get a big washtub and put water and a lot of salt. Throw live ones in and wait 30 min. This allows the evacuation of mud, sand and "stuff". Then take them inside to boil with cajun spices. I observed my daughter as a teenager do this. Funny as he//. She was taking a culinary course at the jr college. It didn't last as she's 5' tall and weighed 105. She just couldn't pick up those heavy pans and we'll not even talk about the knives. She's 42 now and a RN so it worked out.
