It occurred to me that this sketch deserves a bit of commentary. It is easily among the best sketches produced by Monty Python. Some of the most iconic Monty Python sketches feature John Cleese and Michael Palin opposite one another: Dead Parrot, The Ministry of Silly Walks, The Fish-Slapping Dance (post 6), The Cheese Shop (post 7), The Bookshop, Fish License.
It seems like a shame for the history of comedy that Cleese and Palin never collaborated together in a close way outside of Monty Python (beyond Palin co-starring in the Cleese films A Fish Called Wanda and Fierce Creatures). They clearly had an exceptional comedic rapport when it came to acting these sketches, as is especially evident when one views live versions of their sketches (post 7). This no doubt helps to explain why so many of the greatest Monty Python sketches star these two. Their physical and stylistic differences also made for a naturally good comedy duo - one that bears some similarities to Laurel and Hardy, and Cook and Moore.
One can only conjecture what could have come about had Cleese and Palin decided to pursue a project outside of Monty Python as a comedy duo, but perhaps this never happened in part because it would have felt like more of the same. After all, Cleese refused to continue taking part in Flying Circus partly because things had become repetitive for him (his then-writing partner Graham Chapman had also become too much of a burden), and he clearly wanted to write with his wife Connie Booth the sitcom that became Fawlty Towers (and it certainly is a brilliant sitcom). It must also be admitted that Cleese and Palin had rarely written together. Their rapport came through acting, not writing. Some of the sketches that star Cleese and Palin were written by Cleese and Chapman (Dead Parrot, Silly Walks, Fish License, Cheese Shop, Bookshop), and some were written by Palin and Terry Jones (Fish-Slapping Dance, Argument Clinic). Palin's writing partner was Jones, not Cleese, thus his decision to co-write with him Ripping Yarns.