TIP: If you are traveling to mainland China soon, the words W.C, washroom, and 'see-saw' will be very useful to know. It is advised to also say this with hand gestures - put your hands together and act as if you are washing them.
One more thing I noticed in China, particularly the provinces of Zhongshan and Zhu Hai, most of the public restrooms are not western style. By the way, I also noticed this in a few restrooms of the Taiwan airport.
TIP: To have access to western style restrooms, I suggest you head off to the nearest hotels, or some of the posh restaurants of the area.
Toilet Bowl, with automatic bowl cover dispenser, in one of the Resto's of Zhongshan
Even has a TV (only thing is, movies are all in Chinese)
However, my Macau and Hong Kong toilet experiences were all convenient. Most, if not all, of the establishments had clean and accessible restrooms. I was also impressed with the number of public portalets prepared by Macau in different areas on New Year's eve - so going to the toilet was never a daunting task for me.
Note: My best restroom experience so far, are the public restrooms in Paris, France. I had to pay but it was ok - they were automated. The doors will automatically open and close; I think each person were given 3-5 mins to complete their 'duty'. Seriously though, I was told that limits were established to prevent illegal activities inside the toilet.