I guess you don't have kids. You buy silica and quartz free playbox sand that has been filtered and baked so kids won't get sick when they put in mouths or throw it at each other. Silica is a lung irritant and quartz can hold radio active gas (radon).

That's why you buy children's playbox sand that is "silica free".

http://www.eichild.com//moreinfo.cfm...roduct_ID=6316

http://www.woodwardsace.com/safe_play_sand.htm

And I don't care what type of media you use you should wipe your brass off after it is tumbled. I don't want to put any dust or dirt in my guns or dies with the exception of my decapping die but even then I wipe the cases off and brush them out before decapping. I like to tumble with the primers out. And in the 20 years that I have been reloading I have yet to wear any dies out. No need to tumble 50 times during the reloading process. Wipe off, brush out, lube if necessary, decap, then tumble. All my loaded rounds have the primers sealed and are wiped down with a silicone rag which keeps the brass from tarnishing.

Jason