I've got a set of rather grotty old brake calipers to rebuild. After nearly 20 years of benign neglect they are somewhat less than sparkling. I do not have access to a bead blaster. I recall Per mentioning that soaking stuff in Royal Purple was a good way to clean up parts (in was in an article or posting relating to the SAAB build up, if memory serves). I don't need them to be show quality, just functional. In fact, these will end up pickled on the shelf as spares.
Can anybody verify the effectiveness of that for me?

