craftgrrl | How to age something...

I'm getting started early on thinking about and working on Christmas presents for this coming Christmas. I was wanting to make some clay props for my friend's kids (a sheriff's badge mainly right now) and was wondering how I'd go about making it have a kind of aged looked to it. I'm going to be using sculpey clay and Krylon metallic gold paint.

I want it to kind of have the look of this one;

With the color and such. My shape will be different.

Anyway, what's a good way to go about doing this? I don't have any kind of distresser ink or ink pads of any kind and I'm really not wanting to buy some just for this one project. So what's a good, cheap way to go about this? Would an acrylic paint work? I will also have words stamped into the object as well. Probably Sherrif and their names.