These String Winders fit on an electric drilling machine or screw driver. I would not use them on a drill, but only on a very slow screw driver.
The idea is fine, it just spins too fast, so there is nothing wrong with the Drill Bits as such, just not a very useful tool for me. Maybe a dedicated string winder would be more useful, but I will stick to a manual crank for now.
Pros:
Cheap and does what they are intended for well
Cons:
Hard to control with a drill machine, but that is hardly the fault of the Drill Bit.