I attached a long line to train recall with chili in combination with an ecollar. when i give the command to "come" i would hold down the vibrate/page button and pull the line/chili in to me. upon arrival I would release the page/vibrate button. their are youtube videos on the subject. if you dont use a line to pull your dog to you, the vibration could freak out your dog and make him scared, so make sure you have a plan before you start this kind of training. I messed up with chili the 1st time not using a line and chili ran under a chair to hide. using the long line to pull him towards me taught him what to do and where to go when that collar vibrates. nick/shock arent needed at all for recall imo and are very serious tools not to be used lightly.