Frankly, I've seen so many things that are on the "not allowed" list let in to the park that I wouldn't worry too much. And I've been behind people prominently displaying those things lots of times at security, and never seen them turned away. In all my years, I've only seen one thing denied entry-a glass bottle, which interestingly was Perrier water, a sealed, but glass container. And I've been denied carrying alcohol (a plastic glass of wine) OUT of a park.