Is it enough? Personally, I feel awkward about saying that slur even when singing along to rap music. At home. By myself.
UPDATE: The apology by Michael Richards on Letterman seemed sincere enough -- no attempt by him to pussyfoot around or apologize "if anyone was offended" or claim he was pushing barriers as a comedian. But my ear was tripped up by Richards' repeated use of the word "Afro-Americans." It's hard to sound more outdated or out-of-touch than to call black people "Afro-Americans." I supposed he could have called them "colored," which at one point was considered polite, just like "Afro-American", but is now dated, at the very least. You can't help feeling Richards is unintentionally revealing his clueless attitude towards blacks if he still thinks they should be referred to that way. Words matter and even in his apology Richards revealed he still has a long way to go before putting his obvious prejudice behind him. Oddly, this NY Daily News article changes "Afro-American" to "African-American" when quoting Richards, which is a significant change they should not have made.