Don't get your knickers in a knot ... Does it really matter where a genuinely funny phrase originated from.
" don't get your knickers in a knot " is a good example, it is immediately understood by most cultures & countries around the world & is a phrase that can be used in many situations.
No matter how many times i say it or hear it said, it always brings a smile to my face & quite often goes a long way to settling down a potentially nasty discussion.
My point is that it is only the really good phrases, those that roll of the tongue easily & are actually funny & popular, will be hyjacked, pinched, copied from other nations ad infinitum.