Has anyone every used them or tried any?
You can get sets for as little as £3
Do they work and are they safe?
Any downsides?

I got some cheap Ti ones that looked like KCNC copies in the pics, the bushing was made of plastic, I binned them after one (short) ride.

Stick with either good known ones like Shimano, or expensive aftermarket stuff like KCNC, MtZoom etc.

I know someone whose skewer snapped whilst diong 30 ish downhill , resulted in trip to A&E then much dental work and he still has back pain every morning to this day.
I upgraded mine to Hopes as i was keen to learn for his lesson.

Any downsides?

Absolutely none.

except that Hopes aren’t much good – for QR nothing is better/safer than XT, and if you can change your axles, nothing is better than RWS for QR.

So apart from death and snapping they are ideal for my kids bikes then?

I’d say they’d probably be alright for kids bike. I’ve done hundreds of miles on cheap skewers. No way would I use anything like that on a mountain bike with disk brakes.

So apart from death and snapping they are ideal for my kids bikes then?

Depends. How much do you like the kid?

They will be on a mountain bike with discs [ 24 ” though]

I can save about £12 ……its so hard putting a price on love but its about there tbh .

Shimano ones are cheap enough and safe, I wouldn’t use anything else.

They will be on a mountain bike with discs

Then its a no from me

Shimano ones are cheap enough and safe, I wouldn’t use anything else.

although not infalible, I’ve had the cam mechanism fail*, and there’s no way to check it before a ride, unlike the hope/KCNC style ones where you can see if somethings not right.

*felt like it was done up tight, but actualy the wheel was barely being held in.

Avoid. Unreliable and noisy.

Problem is that the quality is going to be totally unknown and probably poor. Not worth risking with a safety critical part, especially to save £12!