This "catharsis theory" is not a new idea. I believe, in fact, that it is one of the most widely accepted loads of bull about emotions and psychology. Many people really believe that if they act out their anger physically, they will no longer feel the emotion of anger. Even in the field of psychology, it was once believed that fits of physical aggression could diminish anger.
"Punch a pillow or a punching bag. And while you do it yell and curse and moan and hollar. . . . Punch with all the frenzy you can. If you are mad at a particular person, picture his or her face on the pillow or punching bag and vent your rage physically and verbally. You will be doing violence to a pillow or punching bag so that you can stop doing violence to yourself by holding in your poisonous anger. You are not hitting a person. You are hitting a ghost of a person - a ghost from the past, a ghost alive in you that must be exorcised in a concrete, physical way." John Lee, Facing the Fire: Expressing and Experiencing Anger AppropriatelyThe truth is that research has consistently found that catharsis can actually increase anger! Because activities that are "cathartic" are also aggressive, they can lead to the activation of other aggressive thoughts, behaviors, and emotions. It is much more effective to talk to someone, write, engage in an expressive hobby (art, music), or exercise than to beat up a pillow. Please, please, save your money on these establishments that encourage catharsis. Call a friend instead. Or, if you have a lot of anger and unresolved past issues, pay a couple extra dollars for the dreaded "head-doctor." (In reality, you'll probably pay less!)