Cautionary message to the OCD cleaners out there. Someone gave me a recent gen Ultegra rear derailleur because it was 'sticky'.
Sticky indeed... upon a complete disassembly it was clear that every quantum of lubricant had been blown clean, presumably due to a dip in solvent.
The only worse treatment on a bike would have been spraying it with a pressure washer. Or driving at highway speeds in the rain with a bike on a rack. Both guaranteed to kill a bike in short order.
The only thing I use on the exterior of a bike is a damp rag. In cleaning my bike, I focus almost all of my efforts on the inside parts such as headsets, hubs and bottom bracket bearings.