We think of electrolysis as a way to split things like water into oxygen and hydrogen using electricity, but it has a second meaning which is to remove hair using electricity. An electrologist inserts very thin needles into each hair follicle and uses a burst of electricity to permanently remove the hair. [Abbxrdy] didn’t want to buy a cheap unit because they don’t work well and didn’t want to spend on a professional setup, so designing and building ensued.
You’ll have to read through the comments to find some build details and the schematic. The device uses commercial electrolysis needles and a DE-9 connector socket as a holder. The device can supply 6 to 22V at up to 2mA. A timer can restrict the pulse to 5 seconds or less.