I use Tung Oil and Teak Oil "finishes" which apparently are just linseed oil and plasticizers. I don't mind the glossy coating it leaves, and I actually prefer it. Another property it has is that it hardens the wood and acts kind of like a glue or epoxy in some sense, so it will lock in the wood fibers, especially if you have any cracks or splits for it to get into. But you're right about the wood glue. Its far more effective for locking in wedges. The linseed oil is just for the exterior.