From Edge of Darkness Wiki
Acid Stomach
Effect: A Promethean’s “Superlative Constitution” already
guarantees that she can eat nearly any kind of organic matter,
from filet mignon to a car-crushed raccoon. With this
Merit, the Promethean can eat most inorganic matter, too.
Whether the “food” is a roll of quarters, a handful of sand or
a broken bottle, if the Promethean can get it into his mouth
and down his throat, then it counts as food.
Drawback: This Merit doesn’t give any bonuses to chewing.
The object has to be small enough to fit in her mouth and for
peristalsis to carry the item down her throat. The Storyteller may
also deem that an object’s composition does damage to the mouth
and throat. Glass shards or jagged metal, for instance, could hurt
the Promethean. Still, this Merit grants some resistance to this
punishment; any damage sustained from eating non-organic
material is limited to one point of bashing damage.