The whip as a litmus test for your relationship with your dog.
With whip or stick that we use in training can and should be used as a litmus test for your relationship with your dog.
With the stick you should be:
able to pet your dog and he should enjoy it
able to help your dog using guiding pressure into positions
able to correct your dog and compel him in to a known behaviour
able to activate your dog and motivate him to work
And after all of that if you throw it he should retrieve it and want to continue working with it.