The topic of smacking children was brought to the forefront by parents Andrew and Miriam, who have adopted a "strict" parenting style.
"We very clearly set the boundaries and the rules in the house and the expectations," Andrew said during the episode.
"We do use smacking as a form of discipline. It's one of the tools in the tool box," Miriam added.
"A smack quickly communicates ‘that is not ok’," Andrew continued. "There are boundaries, there are consequences, you can’t just do what you want."
The admission from the two quickly garnered a passionate response from the other parents, with many firmly against smacking.
Donna and her husband Yann, who are French-style parents, were the first to vocalise their anger of the use of physical punishment.
"You’re violating someone else’s body," Donna said.
"We would never smack our child we feel very strongly about this, she’s a little child, we’re adults, it’s a form of abuse."
Later in the episode, Miriam and Andrew tried to explain their reasoning behind their parenting choice.
"We make sure that we have gone through the other different tools and tried different ways," Miriam said.
"If there is a situation that has that purpose or defiance and we feel that in that particular situation that that’s the most effective tool, we ask the child to come to us.
"We don’t chase them around the house, we don’t try to pin them down or hold them, we ask them to come to us and the smack is delivered on the bottom."
While some of the other parents shared their own opinions and feelings on the matter, it was Dr Justin who had the final say on the issue.
"Smacking is a really divisive issue. Statistics tell us that around 50 per cent of Australians still think smacking is ok and frankly it's something that really needs to change," he said.
"The research is really clear, smacking does not serve our children well. It does not help them to grow or to develop," he later added.
"We don’t need to hurt kids to teach them lessons. We need to help kids to learn to be better."
Parental Guidance continues on Tuesday, November 2 at 7.30 pm on Nine and 9Now.