I spent the last week battling the qc file, but managed to make it work.
I made a couple of rough taunt animations as well. The ideas is that:
1. If you hit the taunt button while the key is equipped;
2. You "turn off" like a toy [video 1]
3. You stay still, waiting for a teammate
4. A wild teammate appears
5. He gets behind you and hits the taunt key
6. Starts turning the key
7. about 3 times [540 degrees]
8. You start walking like a toy [video 2]
I was thinking if an enemy manages to get behind you instead. He could also hit the taunt key, and he would turn it either way too much, causing you to walk/jitter fast and then blow up. Or yank out the key and stab you in the back of the head with it. [you die either way]
The key would be tweaked a bit for some of the classes to prevent clipping. [ex. pyro/medic, goes in the lower back]
Oh also, you get to keep your hat on since this goes in one of the misc. slots.