What happens to a performer who plays a larger-than-life fictional character with such conviction the public can't tell the difference between the actor and the dramatic creation?

This is the story of Shane Jacobson, whose title role in Kenny was so persuasive that some thought the movie was a documentary and that Jacobson really was Kenny Smyth, a wide-eyed Portaloo expert who loved his job.

Now Jacobson is about to don Kenny's overalls once again in Channel Ten's comedy-travel series Kenny's World. It's a brave move. Actors who play a well-known character for too long can struggle to free themselves from the association. Can Rowan Atkinson ever be anyone other than the bumbling Mr Bean? Did Don Adams have a life beyond Maxwell Smart? It took Garry McDonald decades to pry himself from the grip of Norman Gunston.

Jacobson has done other work, recently appearing in the stage production of Guys And Dolls in Melbourne. Yet with Kenny's World it seems likely he will cement himself in the popular imagination as quintessential Aussie bloke Kenny Smyth.

Does this worry Shane or his brother, Clayton Jacobson, who directed the hit movie and the new TV series? Not a bit. "I am happy to be defined by Kenny," Clayton says. "We put a lot of work into it, we do care about the character and I love the fact that it has been embraced. It has opened doors for us. Nothing but good things have come from it for us. Ask us in 15 years' time."

Shane adds, with a wry smile: "Kenny is a better person than I am. I need Kenny. If there is only me I am in real big trouble."

Shane's amusing observation is more than simple self-deprecation. The uniqueness of Kenny, in the broad landscape of contemporary Australian humour, is that he is not a figure of fun. He is not a satirical creation but rather a homage to the essential decency of ordinary Australians. He is closer to C.J. Dennis's "Sentimental Bloke" than to fictional figures of satire such as Kath and Kim, Kylie Mole, Frontline's Mike Moore and The Comedy Company's Con the Fruiterer.

In Kenny's World, the nation's most famous sanitation professional presents a themed travel show. Yep. This is the show that could have been called Great Thunderboxes Of The World or International Dunnies For Dummies. It trades on the huge success generated by the Kenny movie and uses the charm and naivety of Kenny Smyth to explore everything from the Toto toilet factory in Japan (if you have never lowered yourself onto a heated Toto toilet your life is not complete - they are the Rolls-Royces of the sanitation industry) to the world's fastest Portaloo at Indianapolis (Don't ask! Just think "world famous race track", "jet engine" and "toilet" and let your mind do the rest).

As Shane explains: "Everywhere we went - from the space program in Moscow to the places outside Delhi where the scavenger women clean people's toilets in the hope that they will be paid with food, perhaps - Kenny was there as a companion, a friend and a person eager to document and help those people. He was excited about all of those people.

"Being on a barge [provided by the king] that is floating down a river in Thailand - he was excited about every crewman on the barge. It wasn't just the people steering the boat, it was about every crewman. He is no more or less excited about any of them independently because he thinks they are all passionate about what they do and Kenny is passionate about what they do and he is getting a chance to see the world. It's like leaving kids alone with toys except that Kenny was doing that with people around the planet."

The Jacobson brothers talk about Kenny as though he is a rounded and real person who exists in a tangible world somewhere beyond their imaginations. Ask Clayton about the kind of Kenny Smyth who will host Kenny's World and he won't talk about what they wanted the character to do; he will talk about a real person.

"Kenny is not impressed by title," he says. "It doesn't matter what you do in this world. It is your humanity that he is interested in. If you are a king or the guy who polishes the king's shoes, you get equal airing with Kenny. He's like a wide-eyed kid with all the wonderment that a child has when he first enters a space. I think others see that in him and they suddenly feel safe."

It is the blurring of documentary and fiction that has helped make the character such a success. It seems only natural and right that he should have his own TV show. Mind you, Clayton recognises that a series about toilets presents certain problems.

"When you tell people you are doing a show on toilets it is not met with the open arms that I am sure the Getaway crew are greeted with when they turn up and say, 'We're going to promote your hotel.' When you go to a hotel and they go to show you their fabulous foyer and you say, 'Can you show us to your dunny instead?', they get nervous."

The result, given the success of the movie, is probably a ratings certainty for Ten. The concept also screams "international sales" but the Jacobson brothers say it has been made specifically for Australian audiences.

"First and foremost, it is a show you can watch with your entire family," Clayton says. "That's what we love about this show. There is something in it for everyone. There's novelty, there's humour, there's heart and there's discovery.

"It is a travel show with a hell of a difference. I think you will be able to watch a show and feel proud that Kenny is out there being an ambassador for us. We are in good hands."

Shane, once again slipping into that strange act where Kenny is someone he knows and admires, adds: "Australia's best sales rep is out there meeting people from around the world. For anyone who has travelled, or who wants to travel and would enjoy spending some of their time with someone like Kenny - a down-to-earth guy - and travel around the world and meet amazing people, then it is not just about sanitation. Let's just call sanitation the pipeline that got us around the world.

"There are some incredible stories. We knew who we were going to meet because of all the research the team had done but it is like a fancy dress party - you just never know what to expect or who you are going to meet and that's what we went through every day.

"We knew where we were going but we never knew what we were going to experience. If people enjoy it as much as we did making it, then they are in for a great time."

Kenny's World begins on Ten on Wednesday at 8pm.