Janitor: I flunked gym, too. Didn't like the shorts. By the way, your number isn't "CALL-TURK," it's "CALL-TUR." It'd be easier if your name was "Cal Turk."
Turk: There's nobody named Cal Turk!
Inside Turk's fantasy: Insurance office. Turk is shown as a white employee of an insurance company.
Turk: [in whiteface] Cal Turk here! We don't sell insurance, we sell peace of mind! But only to white people. Would you like some milk?
Back to reality
Here is that scene:
It seems like a (perhaps racist?) joke about white people. Can someone explain this insurance joke along with the milk reference? What is the cultural/racial context to it?