I dream of making my fortune inventing something along the lines of the
pet rock.

Bamboo ice cube trays? You couldn't twist them but you should be able to
wack them quite hard on the counter? I bet this would sell like
hotcakes. Are hotcakes the same thing as pancakes??

Silicone ice cube tray, within an ice cube tray, like a liner? Even with
leaks, over time, the hard mold around the liner would keep the water
shaped?

Multiple tiny (think springform/angel food) pans in the shape of an ice
cube tray? I think I saw that they now have cupcake pans with push out
bottoms.

Edible ice cube trays where you literally break the tray apart?

If you dropped a tablespoon of water from the Empire State building on a
day with zero wind, what shape would it be in just before landing? If
snow and sleet can fall from the sky, is it possible to release an ice
cube's worth of water to fall thru a freezing chamber cold enough to be
frozen before it lands in the ice cube bin?

Inquiring minds want to know.