Skyrivers, mice do not live long, only a year or 2 at most.
Alter-Echo- yes, "cervical dislocation" is basically a snapped neck and it sure isn't my choice, nor is it going to work for anyone who's squeamish about doing it.
I know there's a specific technique to it, which I'll let someone who does it explain, but a hesitation on your part can make it fail & cause suffering...you have to
be firm & quick, so it's not a great option IMO. I highly recommend the various methods using CO2.