I've had near violent reactions from people when I said "I can hear you chewing." I was a mild and meek kid, and this was after they acknowledged the noise they made.

Any subconscious behavior has to be controlled with a lot of effort and focus to change.

Almost no one I have ever met has changed a subconscious behavior, just because I asked in a certain way.

Walking can be met half way, or I can adjust _my_ gait to match there's. There's no equivalent to an irritating behavior.