The problem is, without literacy there is generally very, very, very little aptitude for learning
So if you can't read you are a thick hopeless lost cause? Condescending you are.
Of the illiterate people I know (I admit I am in the first world so not heaps), the best technique for getting them to read and write has been the computer. It doesn't judge and it is patient. And they are motivated to learn because there is *something* of interest to them. Trying to read the rules about a game. Surfing pron. Racing the typing tutor. Whatever. Try it with any illiterate friends or their children and find something that interests them that needs them to read some simple words.