Cesar Millan, the world-renowned dog trainer, recommends the e-collar as an effective training tool for dogs. The e-collar is a remote-controlled collar that emits a small electrical charge. This charge is safe for dogs and has been proven to be an effective method of training. E-collars have been used by professional dog trainers for many years and are considered to be one of the most humane and effective methods of training. When used correctly, they can help dogs learn quickly and effectively.