Plenty of people would agree with Youssef. The penchant in many Western countries for wiping after using the toilet – rather than rinsing off – is a source of puzzlement around the world. Water cleans more neatly than paper: at the risk of inspiring an “ew!”, imagine trying to remove chocolate pudding from your skin with tissue alone. Plus, while toilet tissue may not be as harsh as pieces of ceramic (used by ancient Greeks) or corn cobs (used by colonial Americans), we can all agree that water is less abrasive than even the softest five-ply.

Residents of many nations have long been ending a toilet visit with water. And that isn’t just true of the non-Western world. The French of course gave the world the word bidet, and even though the devices are fading away from France, they remain standard in Italy, Argentina, and many other places. Meanwhile, Youssef’s beloved “bum gun” is commonly found in Finland.

Still, much of the West relies on toilet tissue – including the UK and US. And compared to anywhere else in the world, these two nations have had the greatest influence on modern bathroom culture, notes architectural historian Barbara Penner in her book Bathroom. In fact, Anglo-American bathroom trends became so widespread that, in the 1920s, they were even dubbed “sanitary imperialism”.