Every once in a while, usually after a long bit of walking, I will find a small hair sticking out of the ball of my foot. This part of my foot will sting a bit, I’ll find the hair sticking out, and a few hours after pulling it out with tweezers the pain will be gone. I suspect that a bit of hair in my sock — either my own or something picked up — will work it’s way under a bit of skin, then slowly push it’s way in while walking. It’s easy to remove and rather amusing.
Looking around a bit online I’ve found anecdotal stories of others (particularly dog groomers working in sandals) having the same problem, but it seems to be more rare and undiscussed than tonsillolith. And yes, I’m sure it’s not Morgellons.