2 C's in a K refers to the denigratory generic descriptor for an advertising treatment for a commercial that features 2 women in a kitchen...The treatment was currently used in the 50's/60's and 70's.
As in: " I've no idea how they won that DADA award - it was a 2 C's in a K jobby"....
I'm not going to spell it out but you can work out what the C stands for!!