I think it would be a funny item! It could have effects like:
- Making people ho frozen on the platforms, jump (screaming) into the water.
- Stop delinquents/photo perverts/graffiti makers and make them run away.
- Maybe if you use the whistle at someone who hasn't done anything wrong, you get a bad comment/review "what did I do?" "I got yelled at!"
It's something small but I thought it would be funny :)