A reader near-and-dear to my heart (and person, as she's writing away in the other room) writes:
The story is very similar, in many respects, to the scene in Pan’s Labyrinth, in which Ofelia is warned against eating or touching anything on the banquet table of the Pale Man (i.e., the monster-guy with eyeballs in the palms of his hands). She is warned of the consequences, yet still breaks the taboo. The result is terrible, yet she does escape.
I’m looking critical studies or readings that go beyond stating the obvious—e.g. "This is, indeed, a common motif in X folklore" or "This motif appears in sources x, y, and z, with variations a, b, & c."—or identifying the motif or narrative as part of a specific (or worse still, universal) tradition—e.g. the Gerbert of Aurillac/Virgilius legends, the legend of Sinbad/Sindibad/Seven Sages, &c. Interpretations and imaginative readings of the scene from Pan’s Labyrinth are also quite welcome.
Addendum: I’ve also spent quite a bit of time trying to reconcile this motif with other "underworld journeys" (e.g., the Aeneid, the Inferno, &c.) and the long tradition of commentary and allegorical interpretation that develops around them, with some degree of success; yet there are still undoubtedly plenty of readings and retellings of the same (especially late antique & medieval) that I’ve overlooked.