Here is what Gunner was refering to:

Cal is known chemically as calcium hydroxide. Other common names are
builders' lime and slaked lime. In addition to its uses in building,
it is used in many industrial processes including the making of hominy
and tortillas. It is made from calcium oxide which is also sometimes
called lime, but more commonly quicklime. C. hydroxide is a fairly
harmless while power (gloves are recommended, don't breath the dust),
while C. oxide is a fairly dangerous crystalline rock-like material
that must be handled with care (gloves are a must and eye
protection). With due care and certain adjustment to the process,
quicklime can be used in place of builders' lime, but it rarely is.
The main exception is in the making of whitewash, blanqueo.

Look here to see cal used in making tortillas: http://rollybrook.com/tortillas.htm

Herbal/Medicinal remedies -- interesting idea, but it sure sounds like
an awful lot of work.