. I,m a mechanical engineer from Germany and started lockpicking about a year ago. I have some commercial tools and some homebrew stuff.
Now to your original question and some posts related to it:
The pin are very small. The pins would only be coupled by the magnetic forces. They would be extrremely weak magnets when made of steel. So the pins could be separated without using too much force. Once separated the magnetic field decreases with the square of the distance. So it will not offer a relevant coupling force. Reversing the polarity may work on the pins but it will affect all pins. Hence they wont separate beause of that. Magnets made from rare earth metal could be strong enough to provide enough force but the material is very brittle and may not survive the bumping or rough handling with the original key. They also loose their magnetic properties at about 80-100°C. This might be achieveable without destroying the lock or its environment.