I once lost a 3/4 full normal-size tube of toothpaste because of one of these limits.

Made me wonder how paste-like something has to not count as a liquid to them. Playdough?

How closely do they look at deodorant? Some stick-form ones are more liquid than toothpaste is.

Thanks to the TSA holding the power, at the very least in the "Well if you have a dispute with my ruling just step to the side and I'll get my manager, hope they wander over before your flight leaves..." way, I have in fact had TSA agents take away my stick deodorant before.

I had never really thought of that, but the ability to make you miss a flight is an amazingly strong coercive power relative to the stakes.

The x-ray scanners usually have bold signs on them instructing you how to opt out. But if you do, they act as slowly as possible to ensure you never do it again.

I opt out every time - I've never used the scanners - and the delay has never been long enough to make me miss a flight.