Cliches...

Generally speaking, a strong writer does not utilize cliches. They're cheap, run of the mill, and pretty uninteresting to read. That being said, this is a business school essay, not Shakespeare. So if you can use a one word cliche to capture an idea that would otherwise take ten words, then you should probably use the cliche. Just don't over do it.

Without having read your essays, I would be concerned that "spewing cliches" (wow, that sounds really uncomfortable!) might be symptomatic of a larger issue. I find that sometimes when I am writing, I will tend to use general statements and cliches as a crutch if I am trying to work through a topic I don't know much about or am not comfortable with. Obviously, you don't want to seem vague in your essays or that you are unsure of what you are talking about, so maybe the focus here should be on tightening up your ideas and essay structure and less on focusing in on individual word choice. Personally, I think people tend to spend way too much time worrying about the style of their essays when the focus should actually be on content. Adcom readers probably couldn't tell the difference between Hemingway and Hawthorne anyway, so I doubt they're going to be that critical about specific word choices that you use.