I suppose that is possible. Getting oil within the bone matrix would be much easier if it was done prior to killing the animal, under deep anesthesia of course, through a microvascular perfusion. Once the bone is harvested, removed of soft tissue, and dried, soaking in oil should only penetrate a very minimal distance (much less than a millimeter) and that would not last very long. So, maybe a small bit of oils are sitting on the surface when you receive the bone from a company but anything lasting in the long term is more likely to come from the oils in the cordovan. The only way of getting oils deeper into the bone matrix that I could envision is through high heat and pressure - not something that is likely to be economically viable as this is an expensive process. I haven't cut cross sections of the bones used for boning and gone through the appropriate staining procedures, I just know about bone and tissue penetration of solutions/solutes. If anyone wants to send me one of these bones, I'm happy to process it in my lab and report back, I've certainly been wrong before. This one just seems very far fetched to me. Let's be practical though - if there is some magical oil that could be impregnated into bone, is great for cordovan, and oozes out as you scrape your shoes with the bone. Why isn't it being sold? We could all just put a tiny amount on the shoe and scrape it around with any smooth object of a temperature close to that (or slightly warmer than) the leather.