Humanitarian organisations have for decades tried various ways -- be it new systems, pumps or subsidies -- of getting people in developing countries to stop defecating outdoors due to the serious health risks concerned.
But despite their efforts, an estimated 1.2 billion people, primarily in Asia and Africa, still don't use toilets to defecate, a forum of experts meeting in Stockholm was told.
For many extremely poor people who are given toilets by aid groups, it becomes the most precious item they own and therefore they use it as a religious shrine or a dry place to store firewood, international development consultant Kamal Kar said.
"What's becoming quite apparent is that the way you actually have an impact on health, development and poverty alleviation is when people adopt certain behaviours," Clarissa Brocklehurst, the head of UNICEF's water, environment and sanitation programme, told AFP.
In recent years, experts have found that the best method has been to shame people into using some form of toilets, even the most primitive sort, to confine excreta.
"It's just a matter of getting them to understand that what is a long established habit is in fact harmful and that you can do something about it," said Brocklehurst, one of 2,500 experts meeting in Stockholm to discuss water and sanitation issues at World Water Week.
She cited the example of India, where 48 percent of the population, or some 665 million people, still practice "open defecation".
"We actually use shame. We go into communities and say to people: do you realise how fecally contaminated your community is?"
"We do 'walks of shame' where you take a group of people and you walk around and you say, 'look, here's some human faeces'," she explains. "And you do this community mapping where everybody comes and says where they defecate."
The maps then show that there's faeces spread all over the community.
"And you get them to realise how disgusting this is, to live in an environment that is totally contaminated," she said.
The sense of shame is then turned into empowerment, triggering community members to take control over their lives and come up with their own solutions that work for them.
"And once they start using a toilet, even if it's just a pit latrine, they refuse to go back to open defecation. So they begin to climb the sanitation ladder," Kamal Kar said.
Such community-based projects, called Community Led Total Sanitation, started a few years ago in Bangladesh and have been "wildly successful" and are now implemented in 28 countries in Asia, Africa and Latin America, according to Kar.
He stressed that eliminating subsidies was one of the keys to the success of the projects.
"Families were spending money on treating diarrhoea and other diseases but would not spend money on installing a toilet because they expected to be given money for that by aid groups," he said.
But removing that option prompted change, he said.