Most boiling is theoretical in the book, as a possible preparation method for dwarves or hobbits.  In Chapter 13, it’s used as a gerundive to describe the motion of the water.

• 01.066 Dump the crocks in a boiling bowl;
• 02.002 boiled water,
• 02.080 and boil them,
• 02.086 and boil them.
• 02.087 “No good boiling ’em!
• 02.092 and boil them next time.
• 05.042 The answer’s not a kettle boiling over,
• 06.074 fry them, boil them and eat them hot?
• 13.048 there issued a boiling water,