It is a crying shame that in this country a man can live a common life of forty years and, without working upon the notion in any way, never encounter a natural sea sponge for bathing to purchase.   It is a renewable resource (only mature sponges are harvested, and they're harvested in such a way that more sponges will grow quickly nearby) and feels and works soooo much better than all artificial facsimiles thereof.   We only buy two kinds of sea sponges; the extra-soft "fine silk" type, which is for cleaning your face and are about the size of a small tangerine, and the hearty-for-bathing honeycomb sea sponge, much bigger at about 5" or so across; a decent fistful for the shower.  

Rinse your sponge well after each use.  Squeeze it out and set it somewhere where it can dry unabated.  You'll get far more lifespan out of it than the fake sponges if you do this (1.5-2 years if you play your cards right), and it will never smell bad like a nasty artificial sponge bacteria factory.  When the sponge wears out, and it eventually will wear, it will announce this to you by starting to become less elastic and slightly slippery.

Go get your favorite hard bar of soap (you'll have to use, and waste, a lot of shower gel with this kind, better to use the fine silk sponge for that) and experience a lost treat in life.

You use the fine silk sea sponge on your face, where they're buttery soft, or if you like a shower gel instead of a hard soap (hard soap = honeycomb sea sponge, gels = fine silk sea sponge).   Great for removing makeup, too.