One of the oldest known examples of steganography is the "shaved slave", as in the example of Histiaeus. You shaved a slave's head, tattooed a message on it, waited for his hair to grow back, and then sent him off to carry your message, hoping that he wasn't intercepted and your recipient at his destination knew what to do with him.
Of course, interpreting the hidden data correctly was up to the recipient.
We just shaved my head last night, as a step towards trying to clear up a scalp condition. It sure looks like all the scar tissue is encoding SOMETHING or other.

Go for it. The more far-fetched, the better. :)
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