Go to Season Five's third disc's episode "The Pie." I discovered this one accidentally, with my DVD-ROM player. My mouse will do the work for me and I just stumbled upon a blooper by clicking on the "TV Listings" button at the upper-left-hand-corner of the episode sub-menu. It runs just under a minute (49 seconds) and is a blooper from the final scene with "Ricky", his boss, and the dummy.
To access the feature with a standard DVD player remote, go to the episode sub-menu ("The Pie"), and up-click three-times, followed by a solitary left-click.