[GG]

I too have a problem using the collar to reinforce sit. Because the next step is to teach your trainee to come on command. My concern is, at some point you're asking your dog to make the determination as to which command you are reinforcing, "sit", or "come". i'm aware that many professionals are using this method and I have no intention to try to convince other trainers that this is wrong. However, i would advise anyone thinking about using the technique to think about it from the dog's point of view. Training techniques and philisophy canges with time, and i'm OK with that as long as it does not confuse the trainee, from my view point of course.
have fun training
GG