The idea of a silent explosive originated, in all places, on The Bullwinkle Show! Bill Scott (writer and voice of Bullwinkle J. Moose) and Chris Hayward ('Bullwinkle' writer and future Get Smart writer) came up with the idea of a silent explosive to be used by series bad guy Boris Badenov. Their original name for the silent explosive: "Hush-A-Boom"
Siegfried's first name is often mistakenly listed as Ludwig, but Max clearly states that Ludwig is only Siegfried's CODE name. His real first name is Conrad, as revealed in "The Mysterious Dr. T" and "Get Smart, Again!"
The Silent Explosive is called "Nitro Whispering".
The title is from the musical "Bye Bye Birdie" with a book by Michael Stewart, lyrics by Lee Adams, and music by Charles Strouse that opened on Broadway on April 14, 1960 playing at the Martin Beck Theatre, the 54th Street Theatre and then the Shubert for 607 performances.
James Komack, Director of this episode, played photographer "Uncle Norman" on MGM's "The Courtship of Eddie's Father" starring Bill Bixby and Brandon Cruz.