A very simple thing washed up in large numbers on the beach, something called a cuttlefish bone. it isn’t really a bone it’s cartilage on one side plus some other softer substance on the other. But it IS the internal skeleton of the cuttlefish. When the cuttlefish dies this is all that’s left and it is light so it floats to the surface and washes up on the beach.
A Cornell college friend, Francis Wu, told me when he was a kid his mother used these to scrub the dishes. One side of the “bone“ is smooth, hard cartilage. The other side is a softer and abrasive substance. When he told me what his mother used them for I tried peeling off the outer edges of the cartilage and using the softer side to scrub some dishes. It’s not only does an excellent job of scrubbing the dishes it also is a biodegradable substance that can be washed off, taken back to the beach and let to wait for thousands of years to become a new substance.
Don’t you dare kill a cuttlefish to get this bone or I will come after you. Joking aside, if you happen to be walking on the beach and see these in quantity, pick one up and try it out. It’s better than buying plastic and having it wind up in the ocean to kill animals and to degrade into microparticles we subsequently eat.