Carbon Disulphide from Thiocyanate?

I was reading about the famous 'mercury thiocyanate serpent' reaction in hopes to make a video on it. I would really like to make the thiocyanate from a mercury salt and a thiocyanate salt, then react it, and then I would like to take the mercury sulphide and make regular old mercury metal- that way it doesn't go to waste ;-).

But here is the interesting part:
I was reading that besides the carbon nitride and mercury sulphide that I expected the reaction to yield, it also makes carbon disulphide!


I've wanted a couple mLs of C2S for a while now, and I cannot find a good place to buy a small amount for cheap. Does this mean that I can take any thiocyanate, decompose it, and get the disulphide? Has anyone came up with a method? I was just thinking to look up the decomp temp of sodium thiocyanate and stuff it in a flask and heat it and condense the vapors. Any other ideas?

Thanks