We discussed this before here-
However, now that everyone is spending a good amount of time with your dogs on environmentally stability, we should revisit what we are trying to do. The goal is that the pup will negotiate an object “because it is there.” A dog that only negotiates the object with cues, coaxing, and/or a reward readily at hand lacks the environmental stability and independence required in a working detection dog.
The pathway we are looking for is not “I’ll do it if you show me the money” but is “I’ll do it because it is in the way of where I am going”.
Remember to not cater to a dog’s weakness, but to instead build your dog’s strength. Present scenarios where he can be successful without your assistance and gradually introduce greater challenges, being careful not to increase the difficulty level beyond his ability to manage it successfully.