We started with the PetSafe brand vibration only training collar. A 1/2 mile range, multiple levels of vibration intensity. That's what the package says anyway. It cost me about $170.00 and I'll be returning it next time I go up that way as it proved ineffective. (If I can convince the video to load, I will post the link to it here).
The problem is two fold, first Kodi is very fluffy, and cannot feel the vibration of the collar through his fur. While many people recommend shaving a dog's neck to allow for better contact the collar manufacturers themselves recommend against this very thing, as it can cause irritation of the skin at the contact site. The second problem is that the collar doesn't actually vibrate much at all, and if that's the case shaving wouldn't help any way. Increasing the intensity on the remote only causes it to vibrate at a higher frequency, that is to say, more rapidly. By doing so, it actually becomes smoother, shaking less. On a bare hand I can hardly feel it myself. I even tried it on my own neck with no results. I played with it for five sessions with Kodi before finally giving up. He simply cannot feel it. There is a chance that it would work on a short coated, and much smaller dog, but for my fluffy boy it simply could not do the job.
Updates later. And some fun updates about the other K9High Ambassadog, Badger, who has been learning to get over his fear of umbrellas.