Those shredded reconstituted blocks of glass that look vaguely sponge like work really well too, though you gotta rinse it down pretty aggressively afterwards and wipe with a cloth cus it gets powder all over the place.
Ah no not those, I mean literally chunks of ground up bottle glass that just vaguely look like sponges. They're not at all actually sponge like in absorbance property.
Hm, then I'm not familiar with what you're describing.