I generally use Chemtech Workshop degreaser or Septone. Both have the same composition. If you are ever in the position of having to use a hammer to remove something from a threaded shaft again, always leave the nut on, unscrewed to level with the end of the shaft such that you are hitting nut and shaft together and use a piece of hardwood or a soft metal between the shaft and the hammer, that way you won't wreck the thread.
