You'd be pushing on a rope. I see nothing good coming from force in this situation especially with an older chessie.
The worst case of this I've seen was with a guy's first lab (English breeding, yellow male). Dog loved pheasant hunting as the guy did some guiding in the fall in SD, but hated water like a cat. After a lot of misery on both sides, reality was accepted, Max was retired from hunt tests and a new pup purchased.
Enjoy your dogs for what they are.