These cables aren't meant for lubrication as they have a self-lubricating liner, and there really isn't a way to lubricate them. Other than just the exposed ends, which should be regularly clean and lightly oiled.
You will hear lots of stories about hanging the cables, putting funnels on the end and pouring in oil, but they are useless procedures.
If your cable is sticking, lubricating it won't help. Or at least won't help more than a very short time before it breaks for good.
Cables are relatively inexpensive. If you think yours is bad, or it feels stiff, or it is simply old (and yours might be 26yrs old) - just replace it. A 15' push-pull cable is <$50.
What you don't want is the cable breaking just as you are maneuvering around other boats and docks.
Mark