How are they supposed to work?

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It looks
like it's meant to be touched to a live terminal and have the current
flow up the shaft, through a capsule which I assume is the bulb, and
then go via a brass end-cap *into my hand*. The last part of that I'm
not particularly keen on.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use. Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of electrical
theory explain?

Cheers,

Pete