Bizman,
English is NOT taught in the area near Charleston South Carolina(Well, it is, but its not what you'd think). According to wikipedia the Charleston dialect is slowly dying out, maybe it is if you are not from the area.....
The folks around Charleston speak Gullah/Geechie, and an American English dialect that has never been accurately copied or imitated. You have to be a resident to actually get it right.
You need to visit the city to really understand how different those folks speak from other Americans. It is far more different than youtube or the net can ever convey.