Cleaning vintage glass and antique porcelain should be done with the utmost of care. Before you wash your porcelain piece you have to remove the dust and the dirt from it. For un-restored antique porcelain you can use a soft brush to remove the dirt and use a mild dishwashing liquid to wash it. Never ever use abrasive cleaners or put porcelain in your dishwasher. Never immerse your porcelain in water completely, it is .