Just bring an empty bottle and fill it up on the other side of security.
The rules as written don’t matter unless you have spare time to spend arguing with the brick wall that is an obstinate TSA agent, and even then good luck. Not too long ago I had to give up a reusable bottle with ice in it. There was a small amount of water from ice melting while in line for security, but clearly much under the limit. TSA agent pointed out how high up the water was in the bottle (which wasn’t that far even, maybe an inch and most of the volume was taken up by ice). It was ridiculous. No I wasn’t allowed to just drink it, no I wasn’t allowed to just dump the ice out. The choice was give up the bottle or go back through security again.
I was correct, and the agent had a bad grasp of what an allowed amount of liquid in ice looks like, but in practical terms she won because I had a flight to catch and she didn’t.
When I fly, there’s usually like, a sink thing near the TSA jawn. Couldn’t you have dumped it out in there or was there not one?
Also, I would have just shoved it in a bag. I have gone over the limit several times (by kind of a lot) and only have been bothered about it a single time going Sydney → LA. (Or maybe the other way around, I forget.)
