This presents an interesting point of consideration. If a saying has its roots in racism, is it still racist if its applied centures later to a completely different context? I'd argue that even if "Dutch courage" was originally in some way racist against the dutch, the racist intent has been stripped away by time. Dutch courage isn't a racist saying at this point, it's just a universally recognised expression for substance-induced courage.
A bit of googling reveals that there's quite a lot of expression with racist roots that we use all the time in different contexts.[1]
A bit of googling reveals that there's quite a lot of expression with racist roots that we use all the time in different contexts.[1]
[1]: It is a cracked article, but it makes some valid points: http://www.cracked.com/article_16967_8-racist-words-you-use-...