It took a day or so to adjust using the collar, but it is by far the best tool - especially for inside the house. Gus learned what the collar is about and I rarely actually use the button. A few times he didn’t have the collar on at all but I picked up the transmitter and he sat at attention.
Finding the appropriate setting took a little trial and error. It does not hurt my dog - it just gets his attention when distractions are more interesting. It is an easier correction vs trying to have a leash in your hand at all times.