In reply to graeme jackson:
> WD40 was specifically designed to Disperse moisture to prevent rust in the aerospace industry - hence Water Dispersant attempt no.40.
> It was NOT designed as a lubricant but has mistakenly found it's way into many households as such.
Not so - Technical Data Sheet (TDS) here: https://wd40.co.uk/product/wd-40-multi-use-product-original/ , which lists its lubricating qualities.
The reason that millions use it as a lubricant is that it is one, albeit with different properties to the stuff in a car engine or gearbox. Personally, a glob of gearbox oil on a creaking kitchen door hinge or a Camalot is not appropriate, but WD40 works well.
Lots of things have lubricating qualities. Water, for example, is also a lubricant, albeit not a very good one. If you were to try, say, Hairless Heart on a rainy day this would quickly become apparent.