Above-the-counter currency-exchanges are still pretty heavily regulated by the Chinese government. See, the ongoing China scam works like this:
* traditional Chinese culture would have the children care for their parents and grandparents in their old age
* one-child policy means that each child has two parents and four grandparents to care for exclusively, so that's not going to work out so well, therefore:
* everyone saves like crazy
* the state-run banks pay negative real interest rates (less than inflation)
* the state-run banks loan to big state-owned firms at negative real interest rates (and you can do amazing things when paying for capital at negative interest rates)
* the people in charge of the state-owned firms live lavish lifestyles off the profits and provide political support for the regime
* from time to time the government has to work to suppress riots over high food prices and other consequences of inflation
This breaks down if the ordinary people can get hold of a currency that isn't full of inflation. So, capital controls limit how many dollars people can get a hold of.
Of course, Bitcoin in the mix could be interesting. Or rendered illegal. Or both.