By spotting do you mean pitting?
Normal use and lubrication should prevent any surface rust from forming on the ways. If there are rust pits I would ignore them as opposed to trying to buff them out. Just keep them wet with oil.
I keep Autosol in the shop to clean up rust spots on my cast metal surfaces. I do not get rust on the metal lathe ways, but can get rust on the wood lathe from turning wet wood. Also can get rust spots on other surfaces due to my perspiration.
A tiny amount of Autosol and paper towel removes the rust fast.