Impossible Cube - Square Plugs

I wanted to print the impossible cube but didn't have any screws on hand. I created a modified model that uses printed square plugs instead of screws.

I suspect that screws might yield somewhat tighter seams (unless you glue the pieces together) but using square plugs (rotated 90 degrees) means no supports needed (even in the recesses, at any angle) and should add to the rigidity of the assembled model.