I spent two months working in a foreign hospital and I talked a lot about it in my PS, as well as listing it as one of my most meaningful experiences.
That being said, I don't know if it did much. I got interviews at places my MCAT and GPA suggested I would. I guess the whole experience was something that sounds impressive to the normal people but to an adcom it isn't that great. However, I didn't do it for them, I did it for myself which is why I don't regret doing it. The language skills that I picked up seem to be the more positive thing that adcoms note.