When you are training dogs, at some point you will get stuck. Sometimes the solution is right in front of your nose the whole time......though not exactly your nose.
First, the back-story: I was taking a walk with an acquaintance and her dog in a lovely arboretum one day. With me at the time, was my adolescent male, Bear. He had about a 90% recall- having done quite a bit of off-leash work with him already. The arboretum unfortunately, was full of very adorable, inquisitive but fast bunnies. As my friend and I came to a fork in the path, Bear shot out in full gallop, down the path we had no intention of taking. My friend calmly looked at her dog and told him to go find Bear and bring him back. We waited patiently for a few minutes. Sure enough, Bear and his friend came running back and joined us on the correct path- no attempts to bolt occurred the rest of the walk. Since then I have used peer pressure to reinvigorate a much older Bear, who was bored with certain drills. If I put another dog in the crate next to him and had him train after the first dog, it created a friendly rivalry. He would shoot out of the crate like a cannonball when it was his turn to go in the ring.
Fast forward to a nearly 10 year old Bear. When I was training my new girl Quinn on bumpers, she insisted on doing a victory lap before returning to me. It was the canvas bumpers with the pheasant wings attached, that she had the most trouble with. All other bumpers were returned promptly. I remembered my friend and thought, now is the time for Bear to pay it forward. The next time Quinn went to retrieve the pheasant wing bumper and before she had time to stall, I told Bear to go get Quinn and have her bring back the bumper. They both came back promptly with Quinn in the lead. She rather smartly, swung her rear around and dropped into heel position, ready to deliver the bumper to hand. Good girl!
Remember that training is a partnership- an older, wiser dog can be a wonderful resource.