Obedience is doing what you’re told to do as soon as you are told to do it, with a happy heart.
Counting to three, or any other number, trains your child to disobey for as long as they can. By definition, this is not obedience. This is also not good parenting. Train your children to obey immediately and they will grow up obeying, many times out of simple habit. But train them to disobey as much as possible and they certainly will — many times out of simple habit.