I had one stock that had so much oil in it, that 6 soaking cycles did not get it all.
I hung the stock head down in my oven and turned it on, gradually increading yhe temp. With a baking sheet under it of course. Around 250 to 300 degrees the oil really started flowing out. I had a puddle of it on the sheet when i was done.
I would periodically remove it and wipe down with acetone to get the oil off the surface.
But like i previously said, leaving it out in the sun for a few days will tell you if there is still oil left.
And with how dark the head of that stock is, it has a lot in it.
