I hear you on this one. When my students make statements that are wrong (either comically misinformed, or bigoted and intolerant), it sets my teeth on edge to not correct them, but I am a guest in the culture. "Oh really?" is my standard response to comments from fan death to homophobia. Sometimes I try to diplomatically respond "we don't believe that in America" but if I offend my (adult) students I could feasibly lose my job. Not always easy.
By the way, would you be interested in doing a guest post for my blog, or perhaps an interview about your experiences in Korea?
Sure, I'd be down. An interview would be cool, or give me some general topic for a guest post (I can't answer "what's life in Korea like" for the thousandth time!) and I'll whip something up for you!