Cleaning Decanters. Those encrusted with the dregs of port wine, will be readily freed from stain by washing them with the refuse of the teapot, leaves and all, whilst warm. Dip the decanter into a ves-eel containing warm water, to prevent the hot tea leaves from cracking the glass, then empty the teapot into the decanter, and a few strokes will clean it. The tannin of the tea has a chemical affinity for the crust on the glass.