So I've recently saved up enough pennies to get a dry tumbler. I've already caught on that lizard bedding made from walnut is the same as the walnut media. I also see that corn cob media's out there. When do you use walnut and when corn cob? The walnut seems to be doing a good job, especially when I occasionally put in a couple squirts of ammonia free Wright's Silver Cleaner and Polish (which also says it can be used on brass). Thanks for the advice.