RKRCPA
Member
I tumble mine in 100% walnut media (lizard litter from a pet store). I will typically turn it on at night and let it tumble to the next day. To keep the dust under control ill put a 5 gallon bucket over it, just make sure you put blocks under the bucket to keep it off the ground to allow air in to keep it from overheating your tumbler. Its best to set something on top of the bucket as well to keep it from vibrating off. 8 hours or so and the brass is very clean.
I've been using the same RCBS tumbler since the early 80's and use this method except I don't use a bucket. My tumbler has a solid lid. My brass is dirty at night and in the morning it's clean. Why mess with success?