Of the 2 options you provided I would use the pinch collar. Now I have mostly dealt with Pointing dogs but what I have seen used for a dog that brakes point to go after the bird is the keep a check cord on the dog and plant a bird in a launcher and let the dog find the bird the dog goes on point and he release the bird and allow it to take flight, if you have two guys doing it one can shoot the bird as the other keeps a firm hand on the check cord and allow the dog to do as it wishes if it takes off after the bird hold the check cord tight and allow the dog to give himself the correction when he gets to the end of the line. Mix this in with letting the dog get the retrieve on command and it seems to work pretty well.

Also I have read you can place the dog in a sit/stay and throw the dummy sometimes let the dog get it some times you walk out and go get it. praise when the dog follows the command and this is suppose to keep the dog guessing as to which action will get him the praise. It is also supposed to teach the dog that not every retrieve is his only the ones you tell him to get.