A lot of actual therapies have been constructed around this idea, and they all basically encourage you to curb your anger by feeding a knuckle sandwich to a punching bag, to prevent you from doing the same to your boss. It makes sense, right? Why throw your wife against the refrigerator when the casserole she under-cooked will shatter to pieces in a much more literal, and satisfying way?
Why it is Bullshit:
Research says it doesn't work. Expressing your anger, even against inanimate objects, doesn't make you less angry at all. In fact, it actually makes you want to get pissed off. Imagine if Bruce Banner walked around all day looking for an excuse to hulk-out, but replace the embarrassing shredded pants with friends and loved ones who are legitimately terrified every time his favorite sports team loses.
See, we humans have these things called "habits." When we do something, and it makes us feel good, we want to do it again... and more often. This is why you don't see a lot of Buddhist monks throwing bricks through storefront windows on their path to enlightenment and Lifetime original movies spend more on broken casserole dishes than on acting. The rush of anger is addictive as hell, and letting yourself lash out as a means to control your anger is like drinking to control your urge to drink.