Cooking: In a large pot over a very hot flame, (those outdoor burners sold through Cabela's for deepfrying turkeys are fabulous), put 1 TBSP/gallon of water, bring to boil, drop in crab, after water is returned to boil, cook for 10 minutes and immediately remove to ice water.
Cleaning: Take the crab after it is cooked, place the crab, top side up, in your left hand (assuming you are right handed). At the rear of the crab, take your thumb and stick it under the edge of the top shell. Rotate forward and lift the shell up, kind of like opening the hood of your car. Discard top shell. Turn the crab over, bottom side up, and you will see down the center of the crab some small shell sections. Put your thumb under that at the rear and lift off, like above. Clean out all the grey and green and spongy stuff (if it looks gross, get rid of it).
At this point you can bag up the half crabs and freeze. Try to suck out as much air from the bag as possible (we have one of those FoodSavers which sort of cryovacks (sp?) the contents). If you have the patience, I will take at least one crab and totally clean it from the shell into the bag and then freeze. This is the makings for another recipe we will share with you soon, Crab Crepes!
For Cioppino, break the crab in half, then twist claws and legs off before you toss into the stew. Like above, I clean the body and toss the cleaned meat in with the whole legs and claws.