I think organizations built around solving more pressing needs will do better. You won't be able to get a person that you are describing to show up to a reading group or to get educated just for education sake. Maybe you could get a person but not many. If you are giving them food when they need food, or helping them get their car lights fixed so they don't get pulled over and have to pay tickets, or helping them fight their landlords and bosses through organizing legal clinics, or helping them get their power back on, you create a captive audience who have the same issues in life and have come to you willingly because you help them to survive. This is more powerful than helping them to be educated or literate, things they don't likely see these as issues of importance in their lives, no matter how wrong they may be about that.