So do you recommend not using treats at all for this, or only just for responding with the cued behavior with the other person being there?
For responding to the cue, absolutely you can give him a treat. But you want to cue Brody as the person is approaching. You are conditioning him that when a person comes towards you, the behavior will be cued. Usually, the person leaving should be a reward by itself but you can give an extra reward for Brody re-engaging back to you if you feel it is needed.
How do you know how long to wait before asking your helper to leave? What kind of sign do you look for from your dog?
In the beginning, the helper leaves very quickly. Literally, as soon as the dog is cued the behavior, helper leaves. Then dog is cued the behavior, 1 second, helper leaves. You can build on duration after that with bouncing the times (1,3, 2, 5) and working your way to a longer time. Even still at a distance.
What signs will depend on your dog. I used this almost exclusively with Jinx. When Jinx feels really stressed, she'll sit and her eyes will get this hard look. Before this however, her ears will go back and then (because she had been conditioned to sit behind me) she'll walk and sit behind me. This is when I'll ask them to leave or remove her from the situation if I can't get them to leave.
For now, if his eyes start to fixate get them to leave. If he goes into a full reaction, remove him from the room til he calms down.
In order for this to be effective, the dog must realize the person is there, be given the opportunity to approach, then be called back to safety.
For running_dog's way, yes. For mine, don't allow Brody to approach. You want him staying in one spot for now.
If no food is given, then he is learning that nothing bad happens, but there is no real counter-conditioning, correct?
No, it's not counter-conditioning at least not in the beginning. It's called Systematic Desensitization. or just desensitization. Desensitization is often combined with counter-conditioning because it's near impossible to teach anything if it is actively being aggressive or being fearful. So you expose the dog to something that's a weaker or less scary version (desensitization) until it becomes able to eat treats (counter-conditioning)
What am I looking for so that I can let the person come closer?
Right now, work on duration. You know, Brody will allow them to get close but he can't handle them that close for that long. So, start a little farther away and a little longer to work your way up. If Brody lets someone stay 5 minutes at 8 feet, then you can let the person come a foot closer. It's gonna take some time. If you can sit in the same room as everyone else with Brody on a leash (and muzzle if you think it's needed) and in a down, that's perfect. Stay still, let him catch his breath and calm down.
Him pulling towards the people could just be that the food is that good in his mind. Personally, I am terrified of crickets, but you pay me enough money I'll have no fear of them. At least until the money runs out
Have you ever tried Brody out off-leash with his muzzle? Or has he always been on leash for all his reactions?