It depends on the person and the situation. I am also more likely to try in a one-on-one setting where there isn't an audience to be played to.

As I think Mark Shea put it though, out of the spiritual works of mercy, instructing the ignorant is one of those that isn't necessarily appropriate for everyone. I don't attempt it in a situation where I know the limits of my patience and charity are likely to be severely tried, and everyone has their own limits.