Elaeomancy, like Encromancy, has the same etymology: (Greek elaion, olive oil + manteía, prophecy).
In the book It’s a Dark World, by Roger J. Boehm, she was described in one sentence as “Divination based on observing the surface of a liquid”
The Wiccan’s Dictionary of Prophecy and Omens, by Gerina Dunwich, suggests reading elaeomancy as a derivative of hydromancy, which does not require separate commentary.
Divination Through the Ages – Contains an equally short description saying that it is staring at the water.
The elamination can also be interpreted as dripping olive oil onto a plate and reading the patterns it creates.