As a Positive Reinforcement Trainer, I am always very troubled and saddened to see Dog Training Aversives still being used as training implements. Aversive versus Positive methods shouldn't even be a debate anymore, but it is, so it's up to us to get the message out about how damaging aversive methods can be to a dog and its behavior.
This article at Preventive Vet explains exactly why you should completely avoid aversive devices and methods. Spread the word! Link: https://www.preventivevet.com/dogs/dog-training-aversives?fbclid=IwAR1KreX7a-FycdcWD-k-TGixs5rBqv_PeLP4ILi1A6MbWz5cdoy-2LLLiM0