shattaf's (North American salad sprayer but for the restroom) work much better then the Japanese toilets, however I would only want to use one in my residence not a public/work restroom. They are common in Brazil and the Middle East, I think the heat makes being "unclean" a bigger issue.
Both shattafs and bidets (which is the whole separate ceramic apparatus, not just the spray) are common here in Brazil. I always though it was because of bigger French/Islamic influence.