John Saunders firstname.lastname@example.org
To start I looked at various official SA websites and could find no mention of anyone having to have an International Licence for a short stay unless such licence was not in the English language. I then spoke on the phone with, I think, the top AA person, who said you have to have an International Licence but then admitted that what they were saying to their members and the public that it was advisable.
It appears some of the many provincial traffic policemen are insisting on an International Licence. While I am sure that if you were prepared to wait for clarification by a senior person or involve the South African Police Force you would win the argument but suffer long delay !
In my view it probably is advisable to obtain an International Drivers Permit valid for 5 years and costing $30.