Matt: I should sing
"The plague it came and fever too
It killed them off like flies
We piled their bodies on the deck
And hove them o'er the side
For sure the dead were lucky then
They'd have to weep no more
Or drag the chain or a perfectly traditional version)

This is about the most shocking verse in folk song that I know,in the context of the rest of the song, and I dont see the point of diverting people's attention from the shocking nature of what is happening in the course of the voyage. Singing "niggers" will just make people think instantly of the appropriateness or not of using that word, and divert from consideration of the power and impact of the song as a whole.