This Mr. Show sketch is slapstick perfection. It comes from season 4 and stars Jay Johnston, who you may recognize from The Sarah Silverman Program. Repetition is a pretty classic comedic device that when donewrong can be torturous.
Although when done correctly can make someone shoot Ovaltine out of their nose. This sketch is definitely the latter. On a funny scale of 1 to 10 this sketch is super fantastic. Aside from the repetitious gag throughout, the folks from Mr. Show also do a stellar job of mocking old-timey chit chat (most notably David Cross).