Thanks for pointing that out; it was wrong of me to make such a bold, absolute assertion, especially without data. It's certainly worth clarifying that I wouldn't expect 100% efficacy from anything involving cultural change; of course it still happens.

And also worth mentioning that the available latrines have to be welcome, clean, and comfortable; at least, better to use than the open-air alternative. Many public latrines are rather less pleasant than a patch of dirt behind a bush.