Retriever training, decoy command

I know waterfowl dog trainers do not like this command for a variety of reasons (dog may crack their tooth on the plastic decoy if really cold or dog may fetch a decoy rather than the duck when hunting), but never had a problem, my dog has a soft mouth, not that cold in Texas, and she sure knows the difference between a duck and a decoy, she has picked up decoys 2 seasons now. It really comes in handy when I throw the decoys in places too deep for me to retrieve them myself.