Ah, that might be a problem than. I had a fairly decent sized backyard, and so long as I seemed to be doing something productive with the fire no one would notice me baking the rocks. I would suggest large and smooth river stones (That's all I could get my hands on during the time), but don't put them directly into the fire. If you're going to use my box method, make sure to the rocks don't burn the paper. Last thing you'd want is to smoke out your snake. And the rocks shouldn't just be "Warm", they need to be hot. Like, burning your hand hot. Don't boil them either, else what you'll end up with a frozen rock that'll break into piece next time you try to thaw it out. Wrap them in aluminum foil if you can spare it. Cloth works too.
