Deep frying works well when the oil is held well above water's boiling point, keeping excessive amounts of oil from soaking in because steam escaping from the food keeps excessive oil from entering. That doesn't work with wood.
But usually you don't want to. The pores and void structures are part of what makes wood, wood. If you managed to fill everything with polymers then what you have is cellulose-fiber-reinforced plastic and not really what people mean when they talk about "wood". (Wood being a tangled, but directed mess of cellulose fibers lightly glued with lignin)
What you're trying to do with finishes is coat the surfaces with just a little more even of a layer of polymer; that includes the pores too, but just their surface and not their volume. Wood had good wicking action and will evenly distribute oil (or water) on its own. If you tried deep frying, you don't have enough time for the oil to evenly distribute.
