Travel with liquids--the viscosity test

In Stephen Colbert's discussion of the liquids he takes with him while traveling (on YouTube), he asked whether custard is a liquid. A USA Today "Today in the Sky" blog entry on "Putting TSA to the viscosity test" reported on the author's experiment to see what she would be forced to discard. She carried a number of items in her bag to the screening area at the Baltimore airport for a flight to St. Louis on Friday night. The items were a container of Silk soy milk, Edge shaving gel, Ban deodorant, a small container of yogurt, a sealed two-pack of Advil capsules (gel caps), some makeup items, and a packet of mustard (see photo).

She was only required to discard the soy milk, one of the makeup items, and one other item (the mustard?).

I don't remember the details and cannot verify them because USA Today has removed the blog post, probably on the grounds that it encourages readers to test the limits of security screening. But shouldn't the rules about what is permitted be clear?

Is water in a frozen state permitted?

Are there any beverages or food items which have the properties of being thixotropic (solid until shaken) or rheopectic (temporarily solid after being shaken)? There's now (at least temporarily) a market...