This one was bouncing around in my head the other day:

Drink new Patio
Diet Cola
refreshing way to stay slim!
It's sugar-free, low calorie
get true cola taste,
while you trim.
Try it, Patio,
Buy it, Patio,
Diet Cola today!

It's possible that I have "Try it" and "Buy it" transposed.

Patio Diet Cola was a Pepsi product back in the sixties, I believe.

Don