1) That either of you are trying to equate killing a human with killing a lobster says all that needs to be said here.  Just crazy talk.

2) Using that hatchet is probably a faster and more certain way to kill the animal quickly.  Depending on a special device to electrocute it means you can never be sure the device will work correctly & raises the cost of killing dinner.  It also takes care of the squeamishness factor involved in actually killing something by making it seem "bloodless and humane".  It's not.  Sadly, I must go down the road of comparison here in spite of point (1).  An axe-man or a guillotine, or a firing squad were a quick and sure way to execute someone, but not bloodless.   So we went down the road of hanging, and electric chairs and gas chambers and now lethal injections to spare the feelings of the observers.  None of these methods are less painful for the condemned and are sometimes horrifically prolonged and agonizing.   Stick with the hatchet.