If it fits, it works. (also known as 'Screw It')
Cons: no privacy, no toilet paper, you can't lean back, it might collapse, very very cold.
Pros: the front side of the box looks like a hungry face.
It also triples as a health test. If the milk jug starts to melt, please see your doctor.
If only that were a Coors can, you'd know exactly when not to get in the shower.