12V toggle switches should be no problem if your switch meets the amperage requirements of the CC's transformer. I'm not sure what the typical amperage of those transformers is since I am not very familiar with them. My guess is that they use a lot of amperage.
With a rheobus you have to watch out for amperage too. The LM317T buses can only handle 1.5A@12V per channel. LM350's can handle 3A.