This program uses your dog's intelligence, his fantastic nose, and his ability to navigate the environment via that nose. Your dog will learn self-control when investigating new or interesting things, impulse control when movement catches his attention and kicks in the need to chase, the understanding of what to do when encountering a specific scent, sight, and/or sound, and how to alert any humans to the presence of a dangerous animal.
Snake avoidance is purely about teaching a dog that the sight, smell or sound of a rattlesnake is to be avoided. This is no different than teaching a dog not to cross the street without our approval, rush the open front door, beg at the table or poop in the house. It's also a lot easier then teaching a dog to alert someone to an impending seizure or a dangerous drop in blood sugar levels.
Does it work? Yes. Just two days ago, as I write this, we encountered our first rattlesnake since moving to our current property. I had not yet finished the avoidance training with my own dogs. What they did as soon as the rattle started was: Brynda and Asher ran away and as soon as I opened the back door ran into the house. Micah was barking up a storm at this creature from about five feet away. This is Micah's normal response to just about anything new or that he feels doesn't belong in his space. Temperance was trying to herd it in high heeler fashion, but still staying about five feet away and mostly behind Micah.