This is true, home in Trinidad there are alot of artist longing for exposure, and they turn to us DJ's. I really would help out if the chance is right, but during a dance... As you said people don't really take well to songs they're not familiar with.
I say, use them in the early part of your event and way down to the end. This way if it is not embraced the reprocusions won't be to devasting: like killing a vibe, no DJ wants to do that.