Absolutely, as long as you don't actually use it. I've used boxes for several costumes over the years. I'd get (or build) a big square box only slightly longer on a side than the width of your torso. One side must be open, so fold the flaps in. Fold the flaps rather than cutting them off as this helps keep the box square and sturdy. Cut a head hole on the side opposite the opening and arm holes in corresponding sides. To give the look that it is a cube being turned, I'd "turn" the middle horizonal row. Make some corners from scrap cardboard and secure to the centers of the horizontal row of the box. Cut out the existing corner pieces on that row. Then use strips of carboard to bridge the gaps between the turned corners and paint! 2 days, tops!