Use regular isopropyl alcohol to remove glue residue from glossy porcelain. First, very gently remove what you can of the glue with an emery board, then use a clean, soft cloth dipped in the rubbing alcohol.
Also, great for cleaning the crystals on chandeliers! Simpy wipe the crystals with a cloth moistened with alcohol.
A sink full of warm water (not hot) mixed with 1/4 cup of clear ammonia is an excellent glass cleaner. Soak for a few minutes, rinse & dry. In your bathroom sink, use warm water again and a tablespoon or two of ammonia to soak combs & hair brushes to clean them. Use an old toothbrush for scrubbing as needed.