Way back when, maybe during the late-1980s, I tried the original. It was called “Epilady,” and it had spring coils. At first, the device worked well and didn’t hurt much. It was very subject to failure, however, and eventually stopped being effective and became painful. I recall that replacement heads were sold separately; I bought and installed new spring coils a couple of times, then I gave up and discarded the device.
Newer versions use a tweezing effect that’s supposedly more effective. But, I’ve read negative reviews, saying that hair may snap-off, rather than being pulled-out, leaving razor-like stubble. Because of these reviews, I haven’t taken the plunge and bought a device.
I’ll be interested in more Jelly comments.