Flipping a bathtub over is never a good idea unless that bathtub is the Disambigua Rotating Tub from DiciannoveDieciDesign. The Disambigua Rotating Tub is designed to save space, as it can go from tub to sink in one simple rotation.
The Disambigua Rotating Tub has a unique U-shaped freestanding design that is a departure from the typical built-in bathtubs found in many bathrooms. There's no information on what the tub would be made out of, but I imagine it would have to be pretty light if it were to be flipped around several times a day. Are you ready to experience the rotating awesomness of the Disambigua Rotating Tub?