This is an ink bottle, and is called an umbrella ink, based on the shape and the multi paneled sides. Looks like a nice pontil scar on the underside of the base.
This indicates that the ink bottle pre-dates the hotel, as these umbrella pontiled examples generally date from the 1840's up to the late 1860's. Umbrella style examples without the pontil scar date ca 1870- 1880's generally. This style was replaced in popularity by the "cone" shape. Nice find! As for cleaning, I would not do much as it looks pretty cool with that patina. Just get the dirt out and put it up for display!