I don't think that's the actual etymology. From what I can find it was an onomonpia about the sounds turkeys make, and a word for gunk. The second part of it is pronounced differently from the racial epiphet (with a more middle vowel like book rather than a forward vowel like boot), and which I understand to be a separate word with a separate origin. I avoid that one due to its spelling and nearness to the slur, but in a compound word it's less likely to be misunderstood. The original use case of the word by the person who supposedly coined it was for needless verbosity. I could see some English speakers retroactively egg corning it and using it as a pun, or maybe it has an older origin than is recorded or the coiner was dishonest, but I can't find an example or evidence of that having happened. If you have an example or personal experience it being used like you describe I'd definitely be interested. It's also possible that I am misconstruing your claim to be one of etymology when it isn't.