CO2 gas chamber, you can do it with dry ice, or get a compressed cylinder of it.

Here are some plans. easy t do and relatively cheap.

http://ball-pythons.net/forums/showt...Y-CO2-chamber)

http://www.rodentracks.com/DIY_Co2_Chamber.html

When using CO2 make sure that you start off with a slow flow. this puts the animal to sleep. then you increase the flow to finish the job. Starting with the valve completely open will cause the rodent pain.