The snake training I have seen involves a defanged rattlesnake, an enclosed pen and a high powered shock collar. The collar is placed with the probes on the dogs stomach and the dog is led into the pen with the snake; as the dog goes for the snake the collar is "lit up" and the dog jumps. After four or five attempts at the snake the dog will go to the opposite corner and avoid the snake. Seems cruel, but is effective.

Jim