Homemade Battery Powered Vaporizer Question

So I've been looking into making a battery powered vape for some time now. Like a lot of people, I don't feel like spending a large amount of money on something that could potentially get found and taken away anyways. As a result of that, stealth and homemade things are the way to go for me. Yes, I've made one of those horrible homemade 'crack pipe' vapes out of a light bulb, and now I'm wanting to move away from that. So...

My idea/invention is going to fit inside an altoids tin (hopefully). For the battery pack I'm going to be using either 3 AA 2600mah rechargeable batteries or 2 AA 2600mah ones. For the part that will heat my bud I am going to use a coil of nichrome wire, probably somewhere in the 20-30 AWG range. The heating element/nichrome wire coil will be sitting/attached to a rock of some sort in order for it to not conduct throughout the rest of the altoids box but withstand the heat. Now comes to my question. What would be a material that will conduct heat well that I could find around the house or at a short trip into a hobby store or hardware store? Aluminum foil is pretty much out because it conducts, but just not really that well or fast. I was thinking of maybe a thin mesh screen, like that of the MFLB. By the way, if I use metal for the bud holder/heat conductor it CANNOT touch the heating element. Any advice would really help, and I'll post pictures along the way of building it as well as when I'm finished. Thanks!

I already have a huge bulk of altoids tins as well as rechargeable batteries so my price will be a little discounted compared to a weekend project sort of idea. But I'm guessing after buying the nichrome wire and mesh, probably around 15 dollars. Possibly 20 if shipping is expensive.