Terra cotta is a type of earthenware clay, which can’t be used unglazed in the shower, or with food, because it will absorb water in the shower and harbor bacteria.

A stoneware/high-fire clay is aptly suited to this purpose because clay fired to a high enough temperature will not take in any water. To create a scrubber, you may want a clay with a high grog content (grog is a sort of “sand” made from bits of already-fired clay which gives the wet clay more stability and the fired clay a coarser texture). You can also buy grog separately and add it.

In the high-fire range it can be difficult to get the rich terracotta color. This clay is the most red and/or most deeply-colored stoneware clay I’ve seen. In addition, using a red iron oxide stain might make it a little more colorful and shouldn’t change the clay surface too much.