...has been soaked in oil.
It's a vintage coticule. Apparently the previous owner was a big fan of honing oil. I thought that coticules were not porous, but it sure is acting like it is. I can't get the damn oil out of it. I've been brushing it like crazy with Ivory liquid, Goo Gone, and every other degreaser I can find. It still has oil in it.
I've even lapped it. It's totally flat now, and there is not very much useful thickness left in the yellow side, so I really don't want to get too jiggy with further lapping.
Anything else I can try??