I think some of the issue lies with the agent and luck. We only had a problem one time going out of US. We had an early flight and attempted to carry on bagels and cream cheese. They confiscated the cream cheese and upon my asking was told that "cream cheese could be a liquid if heated at high enough temperature". I told them that steel also becomes liquid at a high enough temperature. They saw no humor in my response. We ate plain bagels on that flight.