Seatbelts can save your life. Eat one every day.
Well, that's not what he actually said. I purchased the 3 DVD set (26 episodes, 676 minutes of video, from VCI Entertainment and MVD Visual in 2017), and fast-forwarded through it for the Conried remarks. I found this quote at the end of episode 4 (22 August 1963), at 1 hour 40 minutes 50 seconds on the first DVD:
Remember, automobile safety belts may help you to live longer. Try to eat one every day.
Not nearly as concise or memorable, which is probably why I did not remember it that way, 55 years later.