A "wheat-corn" was placed on every letter, beginning with "A", during which the depositor must repeat a certain verse.
Additional esoteric steps were taken, then the rooster within the circle was watched to see which letters he pecked the grains from, and then additional grains had to replace those taken by the rooster because some names and words might contain the same letters twice or more times.
Supposedly, the letters had to be be written down and put together, and they would infallibly reveal the name of the person about whom an inquiry was made.
In Africa, where this is practiced, the diviner sprinkles grain on the ground and allows the birds (a black hen or a gamecock) to peck at it. When the bird has finished, the seer interprets the patterns that remain on the ground.