There are restrictions on alcohol, either hide your stash or restrict quantities. (100% duties on alcohol)
On exit back to South Africa. The South African Environmental Authorities will prohibit fresh fruit and vegetables entering South Africa.
Please also restrict fish quantities imported back into South Africa (Usually 2kg per person) of pelagic/game species. But You supposed to have a licence, purchased in Pretoria, to bring this fish through the border, No, bottom Reef fish or endangered species allowed.