I only eat out of one ceramic bowl, and I clean it with my finger. If I cook stuff in my pot, which is stainless steel, I clean that with a piece of steel wool. Anything that is abrasive will work though, where I have lived where the running water is from an outdoor spigot, I often have used gravel, dirt, leaves, chips of wood, etc cause that's whats around, its how I clean all these animals bowls too. Dirt works well when you don't have hot water because its absorbent. There are substances like chicken fat and marrow just make everything greasy, that's when soap is helpful but also realizing you aren't going to die from a little old fat is also helpful. It's weird that I had this conversation IRL today, get out of my brain internet.
