Elsewhere in toilet news, Asda has been less impressive in the hygiene stakes.

It was left brown-handed this week after a three-year-old slipped in its Wallington branch and found himself in the poop someone else had left behind. "We are appalled someone would do this," parped Asda opting to focus on the doer of the deed rather than staff's failure to clean it up. "As soon as we were alerted, our priority was to look after [turd-tainted toddler] Cassius and close the aisle for immediate cleaning."