Here is the quote from the other thread in connection with flying to Namibia through RSA:

"Recently a rifle agreement in SADC countries were signed which will be in
place from May 1, 2004 onwards.
It imply the following for our clients coming via South Africa (Johannesburg) to Windhoek and it will be a problem for all SADC countries,
e.g. clients being in transit at Johannesburg going to Namibia, Zambia,Zimbabwe or Botswana.
The client will arrive at Johannesburg with his rifle and before he can depart, they require an import permission from Namibia or whatever country.
The Namibian police does not issue any permit without having seen the rifle,you can imagine what mess they will do in issuing permits with wrong
numbers, etc. Thus, the rifle will stay at the airport and the hunter may take it back to the US after the hunt is over, or he might change his hunt
to a South African place.
Different organizations are actively involved in solving the administrative
SADC legislation.
If they can not solve the problem, all land-locked countries (Botswana,Zimbabwe and Zambia) will loose a lot of hunters.
Air Namibia already organized with Air Singapore a flight via Frankfurt to
land in Namibia, and then there is no rifle problem anymore."

I do not know if this is still the case, so I would recommend checking it out thoroughly before trying to fly through RSA. If it were me, I would just go through Frankfurt and not worry about it. The hell with "The Wonderful New RSA" and their political games.