Blatty was a contestant on Groucho Marx's You Bet Your Life. He pretended to be an Arab prince, complete with a fake accent. That wasn't a running theme on You Bet Your Life or anything, that was ... just something he did.
This was back in the days when doing something super racist on national TV was still seen as a smart career move.
Blatty won 10 grand on the show, and used the money to quit his day job so he could focus on writing full-time. What we're saying is clearly that the offensive foreign accent you do for your friends at work might be profitable some day.