First: person A stretches out person B's anal canal by inserting the middle finger, index finger, and thumb into the bum- and spreads the fingers.
Once anal hole is stretched:
person A inserts the head of a mop- preferably new- part with threadsinto person B's bowels, jiggles mop in order to clean person B's colon.
And that, my dear friends, is the ULTIMATE chimney sweep.
person A: No problem, I'm glad I could help with your constipation.