Did you know the phrase "nitty-gritty" is a racist term, and in UK you can be disciplined
for using it. Somebody allegedly discovered that it referred to detritus in bilge of
slave ships. Believe it or not. Here is URL to BBC story:
http://news.bbc.co.uk/2/hi/uk_news/politics/1988681.stm

Quinion says nitty-gritty first recorded in 1950s/ So "slave ship" origin seems impossible.
http://www.worldwidewords.org/qa/qa-nit2.htm