This is your second post under the Ducks topic, as well as your second ever on BYC. So welcome to BYC! How much are you willing to spend on shipping?
Now, you are, according to your other thread, looking for dead, frozen ducks to train your dogs. I have no objection to hunting. But I can tell you it's not going to go real well here, since most of us are focused on keeping our ducks happy, healthy and alive. If I did lose one to illness, I would gladly freeze it and give it to you, but would you want your dogs training with a duck that had died of unknown cause? That could possibly make your dogs sick? Nope. I'm betting the dogs are more valuable than that.
I was trying to think of an alternative method for you, but pretty much any way you get ducks, other than by hunting, is going to carry a risk to your dogs. Not to mention, freak out a bunch of pet duck owners!
You might consider the tried and true method of training decoys instead. They are reusable, which is another strike against frozen ducks. And since you need only 4, I'd suggest you go to the local grocery store and buy ducks, should be plenty available with Easter coming up.
Probably won't be Mallards, but do the dogs really know the difference?