Perhaps you could also wind thin-ish non-stranded copper wire around a door handle, as if on a spool. This might easier to obtain for some people (or they already have it at home) and won’t have the sharp edged that can cut your hand. If it does not want to stay in place, perhaps also put double-sided adhesive tape under it? Haven’t had the opportunity to try this yet, just speculating
Beware, some of the very thin bare-looking copper wire you will find is “magnet wire”, which is actually coated in a thin layer of clear insulation.
Good point. You can try measuring it with and ohmmeter from the side, there should be ~ no measurable resistance.