Don't know much about slingbox, I looked it up onthe internet and it's not that clear. I understand that the way it works is that you have your satellite receiver in location 'A' and feed the signal through the 'slingbox' over the internet so that you can receive it in location 'B'.
In this case, location 'A' would be ZA where you can legally receive DSTV and are subscribed to it, and location 'B' .... I'll leave that to your imagination!
I hope someone with a bit more knowledge can inform you better than I.