I don't wish to argue with you, you being the site owner.
However, being a retired police officer, I would never advise someone to shout at people and or use bad language. Besides not being the best way to conduct yourself, it can result in an negative affect in person interactions, in fact the very opposite of what you want to achieve. By all means put you point across, but do so in a level and composed manner.
By the way, people can have an enjoyable time at work, thats how you get the best out of people.