Thumblers tumbler help needed

[Sitting Bull]

Hey guys, I just bought a Thumblers Tumbler off a lady for $10.00. It is the small rotary one with the square motor housing . Any way it will probably only hold maybe 30 pieces of brass, but thats OK with me. It also had a box that says 300 grit with a bag of fine white powder that was labelled polish.I am not sure that the contents are exactly as labelled.
Well my question is for those that have experience with this brand of machine , How do I get started with it. Should I get some dry media? Which would be best?
I have never tumbled before, except when I had a bit to many pops All help and comments are welcomed.
Thanks

[Silvercreek]

When you polish rocks you use varying grit sizes with the final polish done with that white powder.

[Sitting Bull]

so can the stuff I have be used on my brass cases?

[M70]

I have the Model B version that can hold hundreds of pieces of pistol brass and I fill it about half full for rifle brass. I've used both corn media and walnut media with a little bit of nu polish in it. I fill enough media to just cover the brass and I don't generally have to run it for very long. An hour and a half is about enough for me. The corn seems to get stuck in the primer holes sometimes but it has been a pretty good unit for me.

I'm not sure that I would use rock polishing compound for my brass though.

[Sitting Bull]

Thank you M70, I'll pick up my supplies and give it a whirl. I figure for $10 bucks I couldn't go wrong. If I find it does not cut it , I can alway use it for rocks with the grand kids.

[Coyotebutcher]

Sounds like a good moly coating tumbler

[6MT]

I use stainless steel pins as my media. Add about half the drum with water, and then a small amount of Lemon Shine.