I read and received many information about the dirty toilet in china.

In China, all 3, 4 or 5 stars hotels are equipped with clean western toilets. In most of the sightseeing spots, clean wash rooms are available. For going to restaurants, you may choose the fancy and decent ones instead of small restaurants or food stalls, then it should be no problem. And also you may tell your requests to the guide, who will help you to find clean toilets on the way, such as the ones in KFC or Starbucks. While western style toilets can not be guaranteed all the time.