My Grandma used to say that WD40 worked for her aching joints and she swore by it and used it whenever her joints would ache.
But in reality it doesn't work as I've tried it and when you think about it the WD40 could not help the aching joints when you put the WD40 on your skin because the joints would not get the WD40 onto them so the WD40 could not really fix the aching joints at all.