So I have to admit something.
I inadvertently had a bottle of H20 in my roll-a-board this week.
Despite "Condition Retarded" being in full force, and actually having my bag run through twice, the offending agent was not identified or confiscated. I only realized this once I unpacked at home.
So either this is complete Kabuki, screeners think it's nonsense, screeners can't clearly visualize liquids in the Xray, or all of the above.