I think it’s accurate to say the intention was to highlight the ugliness of racism by offering a parody of the kind of attitude that existed, pretty much in the same way that you might see in a film these days. The song ‘Rhodesia’ contained political comment, if I’m not mistaken. To put it in perspective, the N-word was still in common use amongst racist people back then, it was commonly spouted in the suburbs of South London where we all grew up and we found it offensive. I believe it was intended to sound ugly/shocking in the song to highlight the racism that we were witnessing. However I’m not the writer so I’m only giving you my interpretation.