No one is sure if a method will be successful until it is actually a success. No one has ever gotten 5 Qual jams in one season with a Golden trained without compulsion and force fetch, until now.
I'd be willing to bet that joe schmoe training his first dog with a collar and all the normal stuff is also uncertain about their method? Certainty and confidence only comes with certain success.
Were you certain that you were going to finish the last series of any trial stake before you got there?