While hiking is it ok to allow my dog go out on a long line and sniff while wearing a prong collar? 

I have a 2.25 Herm Sprenger on my 17-month-old Golden Retriever. We just started using it for walks and it is helping greatly. He seemed to automatically adjust. I have put a lot of work in training wise since day one - he has a couple of tricks titles, we are taking agility classes (he loves!), we've trained for basic obedience regularly on our own and in classes, and we are working on heeling for novice rally. He does well, but pulls toward other dogs (over aroused/friendly) on walks. I don't let him greet them while on a lead.

We plan on taking a lot of hikes this summer and I don't want to send him mixed messages. When we walk, I say "With Me" and he walks beside me on the left. When hiking, is is it okay to say "sniff" and let him go out on a longer line (10 foot line) while wearing the pinch collar? I would, of course, give him the command to come back with me if we pass other people on the trail.

Thank you!

Okay -- thanks so much for responding. He's at that age where he's still an adolescent, but showing these amazing signs of training sinking in and also still showing signs of so much personality in his adolescence. I always feel like it's a balancing act of learn this, but keep your enthusiasm and love of life. He has a lot of that. lol