Without the slightest bit of exaggeration, or embellishment:
I travelled from SYD via several US destinations to arrive in LHR with a full sized deodorant can in my carryon. Not one of the many xray checks deemed it to be a binary component or anything similar. On departure from LHR, the xrayer asked me to produce the can, which by this time I had forgotten was there. She said "this is over the size limit" I will have to take this. Now, I had plenty of time, and felt like working out her rationale behind the seizure - not to be an arse, just for understanding. I asked that didn't the rule govern liquids? The can certainly contained a liquid, but produces a powder & gas mixture once the container is opened, and I demonstrated this fact to her, remembering I forgot to use it that morning. No, it is a liquid, so I have to confiscate it. I relent, as I wasn't going to provoke the authorities into heightened mode....
Not such a big deal, but I wonder how much thought went into the reactionary "standards" that we comply to these days???
Anyway, I dread LHR every time. Combine it with being forced by the business to fly BA makes the experience a very sobering, frustrating experience!!!