OKMy point was that the clay here that sandlappers ate has kaolin.
Do you suppose the show knew, when they had a Q on that term (I gotta go back & check if they really used that term; they used something with "sand" in it) it was derogatory? I didn't, & even the cursory lookup I did when you used it didn't tell me.
By the way, the 1st I heard of this phenomenon ("dirt eating") which has some clinical name I'm not remembering is when a friend in Arizona almost 40 years ago said "I wish they had some dirt here I could eat"; after which they explained this is what people did sometimes back home; back-home for them was not SC
By the way, various medical people have postulated that "dirt eating" & "metal eating" is done by people with metabolic deficiencies who are subconsciously going after what they know will replace an item for which their body has a deficit. But I dunno that anyone has ever proved a metabolic need for aluminum. The current TV show "Three Rivers" recently used a patient's iron-object-eating trait (which of course included intestine-puncturing scissors as well as simple nuts & bolts) as a clue that the patient had an iron deficiency due to some real medical condition (I forget its name).