The WTO has now weighed in on the issue of public urination and defecation. No, not the World Trade Organisation, but the World Toilet Organisation.
"Public education at points of entry could be useful," said WTO's Singapore founder, Jack Sim Ruihua, following the controversy sparked by an online video of a mainland couple allowing their toddler to go to the toilet in a busy Mong Kok street.
"Make the message clear that people will die if they keep doing that," he said. "The flies will go to the poop and spread disease."
Sim said Hong Kong should help mainland visitors understand the importance of hygiene, and offered his organisation's help to create a memorable public education campaign.
With initiatives like the "Don't Eat S*** Campaign" and "Potty Parity", the WTO brings humour to a serious and, usually, little discussed public health issue.
Hong Kong, Sim said, was particularly sensitive to the issue of disease after the Sars crisis in 2003 - which killed 299 Hongkongers - and outbreaks of avian flu, among other epidemics.
Sim advised Hong Kong to enlist the help of celebrities for an aspirational campaign. "Something like, 'Toilet habits reflect your dignity'," he suggested. "Most people don't like to be disgraced. Make hygiene a status issue."
While the World Toilet Organisation sounds kooky, it is linked to serious players, like the United Nations Environment Programme, the Asian Development Bank and the Bill and Melinda Gates Foundation. It has more than 200 members and its current chairman is a graduate of the school of foreign service at Washington's Georgetown University and Harvard Law School.
Sim said the issue in Hong Kong would not be fixed overnight as large parts of the mainland were still developing and people there were learning the importance of hygiene.
He added: "I am sure there are people from the mainland who don't act this way, who are upset that Hong Kong people are bundling them in with people who do.
"They will be scolding their own and that will be helpful."