"Once it flushes it sprays the interior of the bowl with electrolysed water," explained Toto spokeswoman Lenora Campos.

She said the "proprietary process" essentially turns the water into a weak bleach.

"This bleaches the interior, killing anything in the bowl," said Ms Campos.

That makes it super-hydrophilic - or water-loving, so nothing can stick to it - and also photocatalytic, enabling oxygen ions to break down bacteria and viruses.

"You don't have to clean the toilet bowl for over a year," said Ms Campos.

The BBC asked several of Las Vegas' hotels if they might be interested in such a product, but all declined to comment.

However, one smart home expert said the device proved there was still space for innovation beyond hooking things up to the internet.

"It illustrates the notion that tech breakthroughs involve rethinking things," said Frank Gillett from the tech consultancy Forrester Research.

"It's not necessarily about adding anything new."

Potential purchasers should be warned, however, that the device does not totally absolve them of toilet cleaning duties since its cleansing techniques do not extend to spills outside of the bowl.