Doesn't matter how many volts it is, what matters is how many amps. A car battery is only 12 volts but it can kill you. It is the amps that count, I think amps have nothing to do with volts. Amps is how much current runs through a wire in a certain time period. I don't know though but I think that is how it is. I don't really like electronics so I am not sure.
My friend made a teaser from a 9 volt battery, hurts like heck. You can actually kill insects with it, relatively large spiders and beatles. Looks like you will have some fun with your teaser.
Also if they are selling this teaser at a local store, and you don't need a permit then I doubt it will be able to kill people.