I was told to put Kitty Litter in my new speaker stands. Was he joking?

I've used kitty litter on some stands with very good results. The stands I had used thin aluminum tubes with glass plates on top and bottom. They had a distinctive ring to them when you tapped them and this came through when the speakers were playing. The kitty litter in the tubes completely eliminated the problem. Dill makes an interesting point about humidity. I haven't looked inside the tubes since filling them so I can't say if there are any clumping problems. I don't live in a humid climate but if you do that would be something to consider. You might leave some kitty litter out in a tub for a few weeks and see if starts to clump together on it's own. 

Gold dust can be used if you have some extra gold lying around. Make sure it's well sealed so it doesn't attract gold bugs.