Well, I did it again.

I left a couple of meat grinder die plates out on a bamboo cutting board, and they stained it gray. This is the second time I've done this. The previous time was on a multi-wood cutting board. Each time, Beloved Spouse reminds me what an idiot I am for doing it again. Each time, I reply that if she left a polymer cutting board out, it would be both more sanitary and non-staining. (...sound of fireworks going off in background. ...or is it...?)
Anybody out there have a suggestion as to how I might bleach the wood, or remove the stain somehow? Water soaking doesn't help. Scrubbing with soap doesn't help. Sanding doesn't help. (These stains are DEEP !) Soaking with vinegar doesn't help. Wailing and gnashing of teeth don't help.
Yeah, I know- - "don't do that." (Tell me something a DON'T know.)
