As the centre of the universe, Thailand sets the rules, therefore it's sufficient for some underiing to issue the notice as and when considered necessary.
I was told years ago that smoking was allowed as an alternative to chewing tobacco due to its adverse health problems considered worse than cigarettes.
Air-soft rifle / pistol shooting a 6mm hard plastic ball are a better option, readily available over the counter at many places. At close range these pack a mighty whack and can be set for rapid fire and will deter anyone very quickly.