"In space WD-40 is not really an option."
Why not? Do you have some special insights? After all, it was developed for use in rockets.
Well, I've never tried it on my own space station so you may dismiss this as not a "special insight." But applying WD-40 in a complete vacuum, to a jammed metal fastener connection that swings in temperature between roughly -250F and +250F, probably exceeds the recommended use instructions on the side of the can.