The "random gibberish" song Dale sings in this episode as a diversion was not made up for the episode - it's an actual song taken from a Three Stooges sketch.
In addition to the song Dale sings, the song played as the final credits roll is "Three Blind Mice," which was often used as a theme song for The Three Stooges.
Along with "Bobby Goes Nuts" this is the highest rated episode on IMDB.
Everyone's story of what happened in the firehouse is similar, but they each have something unique. Bill's story depicts him as fat (and apparently proud of his weakness to various kinds of food items), Dale's depicts him as a muscular, long-haired type, Boomhauer's depicts him as talking normally (whereas everyone else talks like he normally does), and Hank's features them as children who "grow up" into their normal selves when called into action.