Best disciplinary route for 12-18 month olds

I'm having a massive disagreement with my SO that physically reprimanding our son is not the route to take at his age. What worked in your house at this age when it came to discipline?

Edit: lol the ladies of Glow always blowing things out of proportion...

My stance is no physical reprimandation at this age will work and my SO believes that a smack on the hand when he touches an outlet for example is an appropriate disciplinary course. We arent beating our child Jesus!

And yes we have outlet covers...