I agree with Hermit. Your carry on have to pass for many security points while you other lagauge only once when you check for departure and if you are lucky you do not have to open your traveling lagauge in your destination. I did not flight with a zapper before, but I brought a multimeter, nebulizator (I do not how to spell it) silver wires and many bottles of health store medicine to Mexico without any problems or questions.
One thing that I noticed is that depends on what airline you are using. Last december for the second time I saw that American Airlines opens every single laugage and check everything in it. You see them folding and unfolding personal clothes, toys, etc.
Hope this help and have a nice trip. Vacation?
Piedro