The Pacific NW NAVHDA chapter did one last fall. I was out of town, but my wife took our one year old puppy. the trainer said he did exactly what he was supposed to do. Didn't run into any snakes this year, that I know of anyway. So maybe it worked! The training was $40 and took about 10 minutes.
Contact these guys and see where they got the trainer from - I had the feeling he's not in the chapter, nor from the area. good luck.http://www.pnwnavhda.com/