Another one that somehow sprang to mind:

We all like Ricicles
They're twiceicles as niceicles

(that's all I remember)

For Kellogg's Ricicles breakfast cereal, which IIRC were a sugar coated version of Rice Krispies (not sure if you can still get Ricicles or not? Haven't seen them for years).

I remember we had a 45rpm flexidisc of the song back in the 1960s. It featured the Enid Blyton kids' characters Noddy & Bigears (etc.) who at that time were used to advertise the cereal. The disc had a story on it, and the characters kept singing songs all saying how great Ricicles were.

Anyone remember it?