Often by the time they reach the difficult teenage years, parents have no idea how to turn things around.

Foul-mouthed, out of control and out of line teenagers are easy to find in homes across the nation.

The long-running battle between parents and their teenagers has been fought for decades, but how do parents stop tear-away teenagers from becoming anarchists as adults?

• Juvenile boot camp changing lives
• Shocking schoolgirl stunt goes viral
• Party house turns into a crime scene

“I used to drink heavily to somehow mask - or I don't know if I was trying to mask or depress the feelings that I felt. Drug taking was one of my other things that I used to do,” teenager Jono Denny said.

It took a heavy dose of discipline to turn Jono’s life around.

“It just changed me in a way that I spent time away from my friends and family, I was isolated in a country where I knew no one. There was no chance of me running away like I usually did before I went on the show,” Jono said.

Today Tonight's latest family stories

Out of control Jono was sent to South Africa to live with the Bethe family for a reality check on the reality show World's Strictest Parents. His mother Lyndal always thought the answer would be terminal for her drug taking runaway teen.

“I truly thought dead would be the answer,” Lyndal said.

According to Associate Professor Allen Ralph from the Triple P Parenting Program “the problem is that as kids get older, it is just like sitting on a pressure cooker, because sooner or later something is going to give, and that can be quite disastrous.”

More stories from reporter Damien Hansen

Professor Ralph says finding a balance between tough love and free reign is the key to successfully taming teens.

“It is only going to work where the parents have control over important resources that the teenager wants, like money or transport or food, that kind of thing,” he said.

“Strict parenting is a good thing, but like everything, in moderation. Don't hound your kids, because they'll just go away. Like every other teenager such as myself, give a bit of rope but at the same time, pull them back,” Jono advised.

However, according to Professor Ralph, “if they simply come back to the old environment where the parents don't have a chance, they feel hopeless, they've given up and the whole things is worthless.”

Sixteen-year-old Kyle is another troubled teen-come-good. “I don't go out and waste money on alcohol you know, I just work and sit around, keep out of trouble.”

It makes a pleasant change from the Kyle of old whose attitude was horrendous. His grandparents Sue and Graham were left with little option but to pack his bags and send him off to the United States.

“I was the biggest rat bag back then, I still walk past and say sorry to people just for picking on them in school,” Kyle said.

“He's not on drugs, he doesn't over indulge in alcohol, and he's actually settled down and only got one girlfriend, which has been for a while now, which is a plus,” Sue said.

But Kim Patrick didn't have to send her children overseas for their lesson in tidiness. Instead her daughter was sent packing to the living room, her bedroom boarded up by her mother determined for her to clean up her act.

Kim got the result she was after, but so has Lyndal. “He's just much better now,” she said.

“I would recommend, if you think you can handle it, definitely go on the show. Don't sit there and think ‘it's not for me’. You never want to live with regrets and it'll be something that you never ever, ever forget,” Jono concluded.

Check out the latest from World's Strictest Parents

This reporter is on Twitter at @DamienHansen7