I lived in Japan for a year and you'd be surprised at how common these toilets are.
Most toilets in houses and hotels I used had:
Fake water sounds so noone could hear you 'tinkle' (these are common in public toilets too as water wastage was becoming too high with women flushing to hide their 'toilet' sounds and then flushing again once they completed their business
built in Radio
and of course the washing feature - both male and female settings
My friends and I first encountered it in a hotel where we started pressing all the buttons for fun (without knowing what each one did) and ended up in hysterics as this seemingly never ending stream of water started spraying up and out of the toilet bowl.
There is a Simpson's episode where Homer discovers this type of toilet which started spraying like a fountain with coloured lights and music.
Leave it up to the Japanese to come up with such technological hygiene options