Well, I don't know any people who call it a sling blade.
But there are a lot of words people use for vagina. Just check out this Jezebel article. For erotica writers--and readers and other interested parties--what word do you like to use? I have found myself going from "core" to "cunt." I actually like "cunt." To me it's sexy.
Once I saw a romance manuscript that used "massive log" for penis. To me, so not sexy. But that's a topic for another day.