I bought a hammer impact from Home depot and it has no instructions. I'm too cheap to buy a air impact wrench while I'm fixing my car, so I bought this for $20. Anyway I'm assuming that if you wanna loosen (lefty loosy), you hold the hammer impact the reverse way (clockwise) and then beat it with the hammer. Is this the correct way to use a hammer impact?

You can rotate the chuck part about 90 degrees so that the internal cam either tightens or loosens as you hit it with a hammer. For it to work effectively, you have to keep a very good grip on the handle to try and keep it from rotating in the opposite direction of the chuck.