It has no salt and very little red pepper. I can see where it had no taste if you just used a few bags and some lemons. Those bags do have some unique ingredients ... mustard seed, coriander seed, dill seed, bay leave and allspice. These aren't spices we normally think about putting in our crawfish boil, but I occasionally throw in a few bags with my normal seasonings. I sorta like the unique flavor it gives.
I generally use lemons, onions, and garlic, usually all just cut in half. Never cared for hot dogs, sausage or any of the other gimic stuff. I once had a guy who wanted me to throw in a bag of ice on the crawfish after the boil, he claimed it would make them draw in more spices
I do it for two reasons. One, it cools the water down to prevent overcooking. Two, I believe the seasoning absorbs better as the water cools down. I also leave the top off the pot while they soak.
There are a lot of things that people do that may or may not help. Personally I've never had a bad batch and all I use is Zataran's Crab Boil with some lemons, garlic, onions, a stick of butter and whatever other veggies\meats I want. No extra salt because it's the crab boils main ingredient. I've also heard that purging with salt does absolutely nothing, but I still do it out of habit\tradition. I've eaten at others boils that were just as good and they do it totally different. You just have to find a recipe that works for you and go with it. The main thing to learn is that peppered spices do not always equal flavor. Some in my family have a hard time understanding this. Married side.
The ice is to stop the water from boiling and to stop the crawfish from cooking and becoming chewy. I don't think that cooling the temperature enhances the amount of flavor soaked in. And when you dump the basket on the table, you can start eating because they aren't all angry hot.
boil crawfish for 2-3 minutes, let soak for 30 minutes, serve immediately.. DO NOT ADD CORN UNTIL YOU CUT THE FIRE
When they're overcooked, they fall apart- like eating potted meat. This is a shocker to me. Would think if you leave them in long enough for corn to boil- after boiling, they'd be WAY overcooked. That is really surprising for me to read.