Q&A for How to Purge Crawfish

The crawfish will turn a very bright vibrant red color. At that point, you will see the tails curled up and they're done—it usually takes five minutes for them to actually be cooked. But in order to absorb the flavor they have to sit for at least 30 to 45 minutes.

Boil the crawfish for 15 minutes. Then turn the heat off and allow the crawfish to simmer in the liquid for an additional 15 minutes.

No, this would not be considered animal cruelty.

No. First, crawfish can't spit or vomit. Second, the foregut (stomach) contents are not acidic.

Do not use salt at all while boiling them, only use crawfish boil seasoning. You can find it at most stores down south or through online food retailers.

They should have been cleaned before freezing. Once dead they cannot be purged, just rinsed with clean water.

Eating the dead ones: Because you don't know how long they've been dead, and eating shellfish that has "gone bad" will make for a very bad time. Killing before boiling: It is difficult for lots of little shellfish like crayfish, at least in a way that is less potentially painful than the near-instant death of boiling water. Whatever method, you need to thoroughly clean and cull the batch before killing them immediately before cooking, for the reason detailed above.