We are currently going through and doing something like this for our productions spare tooling. We set up a "2-bin" kanban for it. One of the bins has a small assortment of all the different spare tooling for a specific machine and the other "bin" is for rework or scrapping of the bad tooling. I'm unfamiliar with the 2-bin term but it sounds like this is what you are looking for.
It has been working fairly well so far. One thing I would suggest is fully standardizing exactly what will be done for a changeout. We realized about half way into developing the kanbans that a few of the operators were removing a certain part and getting it cleaned during every changeout. After deciding that this was something we wanted to do every time, we had to adapt our kanban to fit that procedure.
Also, you want to standardize the changeover to ensure that the operators are doing everything off line that they possibly can. Without specific instruction, many of the operators will do things while the machine is shut down that they could easily have done after the machine was back up and running.
