A few months ago, I tried creating copies of my home keys in SketchUp. With a few iterations and eyeballing it, I eventually got something that slide in and out of the lock with ease:
It slid in and out of the lock pretty smooth, so I upgraded, added teeth with my same low-precision modeling technique, and iterated:
(There's actually debris for newer failures here too). The key made it into the lock, but was difficult to remove - a desperate yank with pliers did it. The lock stayed locked, so this was deemed a failure...so far.