It is quite clever but would be best employed only with an audience that knows you're definitely not a racist (I'll just assume that's the case for now).

I would be wary of this particular pun, though, because it could be perceived as belittling the importance of racism. Bear in mind that racism is a phenomenon that causes discrimination, persecution and murder. It's not a joke to many people. That doesn't mean you can't use humour in a song about racism, but who is it you want to mock - the victims or the perpetrators? I'm sure that's not your intention, but the lyric here could be perceived as seeking to satirise the victims or those who express concern about those victims.

Randy Newman plays with words in this way, and toys with our expectations. He also sometimes adopts the character of people whose attitudes he's criticising or mocking. But he does that to make a point against prejudices - not to make them seem trivial.

There are probably quite a few puns around the word 'genocide' that you could use. Ones that play on the 'geno' part of that word and then take it somewhere else. But would you do that?

Or a song punning with the first half of the word 'paedophile' in a similar way. Those first two syllables form part of many other words too, with completely different meanings - eg, paediatrician, pedometer, etc - but somehow I bet you'd avoid that one. ;-)

Steve Cooke
Stockton-on-Tees, UK
http://wwww.soundcloud.com/stevecooke