I can only tell you what I do. Once hung, I set the axe, head down in a container or pan or whatever, and pour BLO down the handle until it's dripping with it, letting some pool in the pan. I leave it like that until the handle is dry. This basically lets the eye sit in a puddle of oil and suck up as much as it wants. This is where you start to find out that wood can vary significantly even when it's the same kind from the same place. Sometimes the handle never dries and I wipe off the excess, other times the oil will be adsorbed in just a few hours. In any case, if it is absorbing oil over a few days, then I just keep putting it on until it won't take any more, making sure the end grain gets an extra helping.