I definitely saw it before, but can't recall where, either! Not only that, I was explaining the premise of the ad to a friend who had a Grape Nuts box with very cluttered wording (!) and a yellow (!) background, stated that the picture was indeed "brilliant". He said the box should really have said "Danger: Boys and girls, don't try this at home. You can choke and aspirate on the Grape Nuts going down your gullet". Brilliant indeed.