Skilcraft Durable and absorbent sponge is made of regenerated natural cellulose. Soft and pliable when wet. Compressed for increased efficiency. Sponges-Cleaning Supplies. Each natural cellulose sponge is designed to be highly durable, absorbent, and pliable when wet, making them ideal for everyday use. The sponges are also conveniently compressed, allowing you to maximize your cleaning efficiency.