Channel 4 from May 13, 9-10pm

Forget ‘go and tidy your room’. In Channel 4‘s latest slice of reality TV, teenage advisers get to tell stressed-out families how to put their houses in order. Hilary Wilce is hooked Is there a giant Rolodex somewhere that programme makers turn to when hunting down truly weird families for the latest reality TV wheeze? You can imagine the entries listed under S, for Swears like a trooper; N, for Neurotic as hell; O, for Obsessional or what?; and W, for Wow, what a loser!

Some of them turned up in Wife Swap earlier this year. Here come some more in Trust Me, I’m A Teenager, a three-part series from Channel 4, to be screened from May 13, in which panels of teenage mentors try to improve the internal dynamics of three London families with teenagers - and problems.

Except that these families would be filed under B for Ballsy as anything, because it takes real courage to turn over a fortnight of your life to a trio of unknown, untrained youngsters.

First up are the well-heeled Nevilles, from Hampstead, north London: company director Dad, bossy motor-mouth Mum, and children aged 12, 14, and 17. The Nevilles’ family dynamic consists mainly of shouting. The mentors, two girls and a boy all aged 16, brand Simon, the eldest, arrogant and lazy for the way he hogs the sofa and swears at Mum, and Georgia as a moody teenager who should stop whingeing. Everyone, they say, should listen more to the youngest, Jacob.

But it is the parents who get the hardest time. Dad David is sentenced to be more involved with his children by discussing motivation with Simon, boys with Georgia, and sex with Jacob. His struggle to explain oral sex will have you cringing behind the sofa. Most of all, though, the mentors believe mother Elizabeth needs to get off her children’s back and out of the house - “If she doesn’t work, why does she need an au pair?” They tell her to get a job.

The look on her face at this point is worth watching the whole series for.

But she does. And guess what? She does a shift as a waitress and loves it.

Second up are the inappropriately named Rainbows, also of north London: Mum Jacki, plus Kelly, 15, Russell, 13, Mark, five, and Michael, three. These Rainbows live under thunderclouds of violent bickering and disorganisation.

“It’s my fault,” says Jacki. “There’s a thin line between mate and mum and I’ve crossed it.”

One of their three mentors, 15-year-old Cynthia, soon gets to the heart of the matter. “The little ones went to bed really late - there’s no routine.”

The team lays down the rules: no disrespecting, no voice-raising, no swearing, and early bedtimes all round. Kelly is told to take the burden off her mum and get up in time to get the family on the road in the morning - with disastrous, then surprising, results.

The mentors who skateboard up the street to deal with the ominously named Osbornes of south London come with much more of a teen agenda - perhaps because one of them is only 13. The three Osborne boys, 16, 13 and 11, are totally dependent on scary mum Teresa. As a result, the boys are so helpless that when Teresa is exiled from the kitchen they struggle to make a sandwich. “Is this right?” asks one, anxiously.

The mentors think the oldest boy, Tyler, needs to break out - “He’s such a goody two-shoes. It’s unreal for a 16-year-old to be so straight-edged” - and wave a magic wand over his forthcoming weeks: “No curfew, you can travel home as you like. Your mum and dad will no longer be a taxi service.”

Like a long-caged animal, Tyler doesn’t know what to do with such freedom.

Meanwhile, Mum and Dad are being forced to understand teenagers by listening to hip-hop. “I counted 10 different motherfuckers,” cries Dad.

Like all the better reality TV shows, it is uncomfortably riveting. Much of it is excruciating. Some is touching. Some seems contrived. You feel you should be doing something more productive, but still you sit there, gripped by watching people struggling to feel better about their lives.

And the teenage mentors are impressive - articulate, perceptive and responsible. They favour boundaries, and understand the importance of communication. They don’t like children swearing at their parents, or parents disrespecting their children. They think it’s wrong for the under-fives to spend all their time playing computer games, and for people who share a house not to share chores.

They give all the mothers a particularly hard time (dads are too often emotionally or physically absent), but all three women pay generous tribute to what their young minders teach them. The way in which the teen mentors respond to the challenge of being in charge underlines what all good teachers know: that the more you respect young people and trust them to behave responsibly, the more they will rise to your expectations.

In contrast, some of the teens under observation seem hopeless cases. Simon Neville starts out a lazy slob, and ends the same way. Observing the families as a whole reveals two things. First, that love can wear some surprising disguises. And second, as every school knows, if a child has a problem in the classroom, the root of it will almost always lie at home.