Who is inBOIL from Richard Brautigan's Trout Fishing in America ; the Pill Versus the Springhill Mine Disaster ; and, in Watermelon Sugar and what is their importance?

inBOIL is Old Charley's brother and a drunkard. Over the course of the story, inBoil's drinking worsens, and he subsequently has an argument with someone at iDEATH and storms out, cursing his friends. Determined to live alone by the Forgotten Works, inBOIL is joined by several other drunks from iDEATH. They then form a gang and turn the factory into a distillery, where they make whiskey, so they can stay drunk all the time.