But did you ever notice this tidbit from Gygax in Chainmail?
Boiling Oil: "Have some nice hot oil," said the smiling sergeant. When poured from atop a castle wall, flaming oil will sweep a 2" path downward, killing all figures within it; and at the base of the wall the flaming ail will form a puddle 4" wide by 3" deep, which will also kill all figures in its area. It will burn for three turns, preventing any troops from entering the area it lies on. Any wooden structure struck by flaming oil will begin to burn immediately... [Chainmail, p 23]See how the section is titled "boiling oil" but then switches immediately to referencing "flaming oil" as though it's the exact same thing? Confusing!