OP ~ Do you mean the large sponge-type things that the baby can lie on in the bath so they don't slip? I had one years ago for my daughters and I used a gentle cleanser, like laundry detergent, and allowed it to soak in the tub while squishing the soap into it with my hands. Don't use too much soap or it is too hard to rinse out. Once it's soaked for a good while, you can then rinse under warm water until it runs clear. Don't wring too hard or it will rip. Then sprinkle baking soda onto it and work that in. It helps with odors and mildew. It's okay to leave that in, it won't hurt the baby. Be sure to squeeze out as much excess water as possible and then let it dry on the dishrack or a laundry rack so air can get to all sides of it.
Once you smell mold or mildew you will need to throw it out.
I hope this is the item you were talking about.
at 2:28 PM on Oct. 17, 2009