Milked prostate exam similar to the doctor's office

Comedian Billy Conolly once recounted a prostate checkup where he was seemingly milked by his proctologist. His account wasn’t particularly erotic, and it didn’t seem to take the doctor long to express his semen. I recall seeing a comparable moment in Road Trip with Sean William Scott. Has anyone gone through this? Some accounts of prostate milking imply it involves an extended period of gentle stroking—up to about an hour.