I've used wheat several times when running out of media and it works well. Most any cereal grain that is small enough to enter the mouth of the case will work. You should see how shiny the inside of a combine gets.
It did do a nice job & in a pinch I understand. But I’m never in favor of using food for anything other than eating. Just think if we started using rice to clean all metal things. I bet a bowl of fried rice at my favorite local Asian restaurant would get might expensive. We don’t eat corn cobs & walnut shells. Although … they might be tasty 😋
