SP2's fondness for cat food as a child was uninhibited by external education, (after all, it is said that Romulus and Remus were suckled by a wolf) but your inbuilt intuition knows the paper-slapping noise really did not influence the fondness for catfood.
LOL Nits.
No, that was cured by picking up the dish after dinner with the added effect that the cat's ate their meal at one time rather than sampling and coming back later so there wasn't any for rug rat sp2 to get in to.
Most kids have an instinctive desire to please so rewarding wanted behaviour with kind words, hugs and games (positive attention) works like a charm.
Even kids without that instinctive desire to please others can learn that wanted behaviour will get you nice things (a chocolate chip worked well with sp2) and that unwanted behaviour got unwelcome effects i.e. loud noise, having what she wanted removed or being bodily picked up and taken somewhere where there was no fun. However the cause and effect have to be immediate for it to work and the goals easy to figure out. Reminiscent of every dog train program I have ever seen.
However one must start young. The longer it is left the harder it is to get any results.