'Few' is relative, it only has to be a small number, but small itself is relative - it could actually be 5 million Christians, but if it's relative to the number of Christians out there it's small, but relative to the number of people doing this it's huge (or so I pressume). So if 5 million Christians, particularly, 5 million Christians belonging to churchs who condemn homosexuality pulled this off, their experiences would 1) be fantastic sample data 2) set an example.
Now I'm sure Nat's choice of words weren't meant to be analysed, it was probably meant well and to represent Nat's sentiments, perhaps poor word choice, or maybe not 'few' can be meant ironically and I have used it that way myself. More Christians need to do this. Heck, argubly, not just Christians, but people. Those who discriminate should understand what it feels like to be discriminated against. I applaud the Christian for trying it.
It reminds me of a Religious Education
[1] lesson I had at school, our teacher wanted to teach us about discrimination, so what he did was for the entire lesson he had picked a few traits students in the class and for the entire lesson he discriminated against them and then treated everybody else fairly. Don't worry, he didn't take it too far and make it unethical (people knew he was up to something), but it was an effective lesson because at the end when he started asking questions about it, everybody had all the right answers. Sure they didn't feel what it was like to be truly discriminated against, but it was a decent teaching method none-the-less.