Well, sure, when you manipulate the forex market, you can act to alter the value of your own currency.
We could also use exchange controls to arrest our capital flight which is just draining us.
The trajectory of the current South African de facto Kleptocratic ruling party should worry anyone.
One might argue the currency fluctuations are the result of endemic policy failure in every aspect of the South Africa governance. A result of a ransacked economy, stolen in the guise of altruism by a corrupt ruling cabal.
Closing the economy, removing the scrutiny of outside participants, will only seek to further assign it the moniker as yet another basket case economy
It worked in China only because the size of the country is such that it can basically do anything alone if it wants to, and the outlook was so "inevitably" good (again because of size) that investors were ready to risk it all.
Is SouthAfrica in that position? I doubt it. Imho a wave of capital restrictions in SA would trigger a Zimbabwe-like crisis, making it official that it's all gone to the dogs.
https://www.swissinfo.ch/eng/swiss-franc-climbs-after-us-add... (why is the US treasury telling us what to do? We've attempted to adjust against EUR, so if you all don't like USD/CHF why don't you all work the USD lever instead?)