Actually every country was very receptive, even North Vietnam. We were invited to a school in Cambodia that concentrated on teaching kids English and it was a source of pride for a student for one of our group to sit with them. My wife bought a 10 pack of scratch pads with a colorful cover to give away. You would of thought that we gave them $100.00 they were so appreciative. They would read to us in English.
Even the adults were friendly and would say Hi and allow us to take pictures. Part of our tour was to go into small villages to see how they made things [scarfs, blankets and also jewelry] and of course then to buy things. We also got to tour more then one house both the average house and then a "higher" income house.
These countries are still low income, especially the rural farm areas.