Try brushing on a mixture of 80% Xylol (xylene) and 20% mineral oil. That will get into those hard-to-reach places and lubricate. I have used this rather successfully to restore rusted chains with locked up rivets. The xylene, available at most paint stores, works much better than mineral spirits and evaporates more slowly.WD-40 has solvents, but also lubricants. It will penetrate into tight recesses, displace water (Water Displacing) and leave a light lubricant on the item.
I also use it on chains because I know that it will get between the side plates (tie straps) and around the rivets, even after I have degreased them in some solvent or caustic cleaner. I can't be sure that just dipping it in thick, viscous bar and chain oil will get into those places.
Philbert