I concur about the steel chainmail. I washed dishes in a New Mexican Restaurant when I was younger. The worst was the 30 quart bean pot. The starch and the bean

I concur about the steel chainmail. I washed dishes in a New Mexican Restaurant when I was younger. The worst was the 30 quart bean pot. The starch and the beans. The chainmail made short work of it. But focusing in on the rivets, there are two ways to look at it. The remaining fat that has undergone polymer-type conversion due to heat is seasoning, not dirt. Or if you really want to get in there, probably an ice pick.