Good idea to instruct in SA, however one minor problem - getting a work permit.
Next problem is that due to affirmative action selection for SA based airlines those persons who are oversubscribed in their population group find getting an airline job fairly difficult, thus these people take up instructing to get themselves ahead and then when they have the necessary experience end up working for contractors to the UN etc. in 'interesting' areas of Africa shunned by the more advantaged sections of the community in the new process.
Unless you can get the work permit (unlikely unless you have some SA connection), it is probably not going to be a worthwhile option.