Check out the photos:
My dog passed the ball. Played a lot with her and failed to destroy it, as is common with most fragile toys.
As Melamine Sponges I haven't tested it yet, because I'm still finishing a magic sponge, those that are blue and white. Apparently the white part is melamine, just like the one I bought.
I like these sponges to clean walls. Handprints, dog objects and paws are easily removed with them, using only water, no need for cleaning products.
How expensive they are in Brazil, and spend quickly using, I end up using only on more difficult tasks, but I intend to expand the use to clean other materials.
I also found that on AliExpress you can find melamine sponges in large quantities at low cost. My next purchase from them will certainly be there.