Not really. South Africa's main exports were mainly commodities and anything it imported it imported through proxies (such as Taiwan or Israel). Disinvestment was a major boon to South Africans since it allowed them to buy foreign assets at cents to the rand.
Sanctions also increased the Laager mentality which probability increased the length of Apartheid.
The reasons why South Africa turned to CODESA had probably more to do with the happenings in the Soviet Union and Eastern Europe (since South Africa’s biggest problem was that the ANC&SACP movements were funded by the USSR).
Btw, I don’t know why you say that it worked, when by all objective measures black people are worse off now than under Apartheid (e.g. a 13 year drop in life expectancy). South Africa is on track to become a failed state in 10-15 years.
See this link for a comparison: http://www.reddit.com/r/AskReddit/comments/aja38/nonamerican...