I have had very good success with Dante Trudel's Doggcrap (or Doggpound) training system, and have been using it without gear so far. I am thinking of getting some gear and seeing what kind of gains I could make with it, because the system has been so effective without it.
Has anyone else used this system? What are your thoughts on it? You may want to give it a shot if you have plateaued somewhere in your training. Just Google it, you'll find it