I've learned a lot from this effort. I've been very slow and methodical about it (or tried to be and admitting when I'm not) so that I can observe what's working and what isn't. It's a matter of learning how to teach my horses rather than just trying to get this one behavior taught.
It was interesting to see how Stowaway was able to progress in the desired behavior even when I wasn't as thorough in my requirements of him. This has shown up now, however, in a much weaker performance. He is much more likely to give up standing there to come to me. He was never rewarded for leaving his spot- I always ignored him when he left. However, he was not as consistently successful compared to Ande. Because I was careful to set it up so that Ande was almost always successful, he has ended up being much more reliable. That seems to me to be evidence that positive reinforcement gives you a better result than letting a horse fail (if you can help it). To be sure, Stow hasn't had the background in Clicker Training which Ande has either.
Today I rode Ande (thankful for a beautiful late Indian Summer day!) and left him in the round pen when I was done so that now Stowaway was alone in their paddock. Now I had no excuse not to work with him alone. I tied up the jug...on a different post further from where Ande usually is. The last time I did this was at suppertime and Ande was ready for dinner and therefore did chase Stowaway away from the previously shared spot. What I saw first was that Stowaway was interested and ready- but did not actually touch the jug. So I cleaned that up with ten successive C/Ts for an actual touch of the jug.
From there I proceeded the way I had previously, just as a review and to make sure Stowaway had all the pieces- stepping away one step at at time, going both directions away, rattling the gate, and finally opening the gate and going in. I was able to cruise through the whole process in one session but I think it was important to do it all with him. I'm almost ready to bring out the food when they are at their "stations" but still struggling with how to do it in the most steps possible. Actually, it has just occurred to me that I should do Alex's "You Can't Make Me Eat That" exercise first! That is a great exercise in self control and will give them practice in resisting the urge to come to me when I have food, when they are accustomed to coming to me when I show up with hay. Once I have taught that as a separate exercise, I can combine it with the targeting for my goal.
Another thing I discovered yesterday is how important it is to have a concrete target to start with. I am still using the jug and do not plan to phase that out for a while. But it's going so well that I thought I would begin the same exercise with Rumer and Percy. I had learned enough to want to do them separately and began with Rumer. For them, my goal is to get them to stand outside the barn while I go in. As it stands now, I have one over each shoulder (quite literally!) as I try to open the panel to go in. They are both SO good and I trust them completely that it doesn't concern me, but it is a little awkward. So my goal is to have one stand on each side of the 12 foot wide door. I did not take another jug out and decided I would just have Rumer target side of the door. That just plain did not work. There was even a screw eye in there with a plastic chain on it which I used as my "target" but she has played with that chain so much on her own that she just did not understand that it was about targeting. She stood well and did not mug me, but if I got more than about three steps away from that spot, she would come over to me and assume the same position. She thought it was about Grownups are Talking, not about targeting. So she was very polite and very patient....she'd done this lots of times before. She was willing to wait me out and just stand there. The only way I could get her back to the spot was to take her there. I finally decided I needed a real target and this afternoon I will go back with a yogurt container to tie to that screw eye. I am quite confident that will make the difference.