a common recipe for a finish is to mix equal parts of Boiled Linseed oil,
Tung Oil, and Varnish.

These home brew finishes are never as good performance wise as a quality
commercial product. Tung oil and linseed oil finishes cure by reacting with
oxygen in the air IIRC, and thus poymerizing. By themselves they will take
forever to cure decently, so adding varnish actually adds more of an oil, but
also a catalyst like cobalt napthenate to kick off the cure.
Some people like sticky kitchen cabinets, so it's a matter of taste if you'd
rather brew your own.
As in many things, newer technology displaces the old only because its better.
HTH

Joe