In my opinion its just an average cleaning sponge does the job bought it from target and it was affordable its not something different and does get smelly after using it several times and leaving it damp i wouldn't buy it again
These sponges are a little pricey but sadly anything that's good for the Earth such as biodegradable sponges is going to be pretty pricey they work like a charm they get down in the grit I love using these when I wash dishes
I haven't had them smell and they seem to hold up as well as any other sponge by scotch brite. I guess it would depend on what you use it for? I use mine to clean the tub and to scrub dishes before loading them into the dishwasher.