Remember if you rely on anything that is not you, your dog relies on it too and it is tougher to be successful off leash or with distractions.
Flexi-leashes can cause more problems than they are worth. When your dog is on an extendable leash there is always pressure on the collar unless you have it locked down. So your dog learns to pull against the pressure on the collar to get where he wants to go. Hence teaching the dog to pull his human everywhere he wants to go PLUS he is leading the dance not you.
It also places him in what we call 'recess' brain. He is out in front of you and all around you doing as he pleases not thinking about what you want. Like a child holding your hand but pulling in every direction trying to dictate where they want to go not where you, the adult/parent, are intending to go.
A dog who lives in recess most of the time has a very difficult time listening to you. Their brains literally become wired to be independent and impulsive.
Why would you ever wish to use electricity to try to train a dog when it simply takes good skills, consistency and a sound relationship. Resorting to devices doesn't teach the dog it simply forces him and it doesn't hone your training skills. You do not learn to communicate effectively when you can simply push a button and zap the dog to make him behave. Devices quickly become crutches for the human and don't teach your dog to think.
Love Them & Lead Them,
~Elizabeth & Doug
Dog Training the Way Nature Intended