well, I looked up "Sause", a word that has a certain feel to me, is moderately well known in Germany, if somewhat outdated or old-fashioned, and find a word I have never heard in that context. I then look it up in an online monolingual dictionary to see whether there's a meaning unknown to me (has been known to happen...:-)), and no, there doesn't seem to be. So I put it up here because people tend to look here more than, say, Übersetzung korrekt, and the turnover of entries on display isn't quite as high. To see if someone with a wider vocab. or access to a bigger dictionary can come up with that meaning of "rush" at all. So, as I've said before, I am most certainly not on a mission to impoverish the English language, and I also don't want to seem like the house-critic on Leo, either.
Imagine if that pair wasn't in Leo but you wanted it in - so far, I can't see how it would get in here at all, what with the stringent criteria.
If nothing else, the usage of Sause / rush must be mismatched, if not the entire meaning.
Is knees-up also used in the US, or what would your equivalent for an old-fashioned word for a party be? What did Scott-Fitzgerald go to? Dorothy Parker?