Of course, some player never change, and I've also lived that kind of problem.
But at least, they have to think fast when to declare (or they don't act).
And to limit this kind of trick, our GM ruled that if a player need more than 10 sec before starting to act when asked to, the action was cancelled. Pretty forced us to be careful to hear what HE was telling.
It is a bit dictatorial, but most players understood the point. After that, he relaxed, but at that point, everything was mostly flowing.
Runequestement votre,
Kloster