Did that get your attention?
Well, here's a penetrating/ lubricating fluid that I swear by. It's an American product called PB Blaster. A bit stinky, clear brownish aerosol stuff that beats all others.
No, I'm not affiliated to them, just convinced.
Discovered it when working on a 1990 GMC pickup which had a fair few frozen fasteners. Hand on heart this stuff worked on all of them. Not cheap, but you get what you pay for.
Try it guys, you can find it on fleabay uk.
Keep smilin' Paul.