Charles in Charge was before my time. But, I was originally turned on to it by Flash cartoons made by the Waterman Studios. The first time I heard it was on the boat-themed Waterman five.
[From Waterman Five:
Pal: Who put you in charge!?
Waterman: Charles in charge...I mean...I did...]
I was also turned on by it from Puppets in the Park 4: The Gingerbread Man.
[From Puppets in the Park 4: The Gingerbread Man:
Waterman: The moral of this story is...bring Hardcopy back...and Charles in Charge!!