I was in Rotary for many years. I never personally hosted a student but did things with them on weekends...like taking them to the state fair. Brazil, South Africa, Germany, France are just some the countries I remember. My assistant's daughter was a foreign exchange student and she loved it.
Just one note about the kids, in most of the countries they drink alcohol alot younger legally and that is just part of the culture. The programs DEMAND that they adher to our rules and they DO without a problem but it is odd for them because what is natural to them is illegal here BUT they see all the kids drinking anyway. I probably dealt with twenty of them through the years and every single one of them commented on how backwards they thought the system was.