Do not store foods or beverages in crystal bowls or bottles for long periods of time.
Vinegar, acidic juice, and alcoholic beverages will leach the lead out of the glass.
Porous pottery and ironstone can be cleaned with wig bleach obtained from a beauty salon.
To clean glass with an irridescent finish, use cool water and very little mild soap.
Very hot or very cold water can cause sudden stresses to glass, particularly where the glass is thick.
If the inside is badly lime-scaled, Probably the best DIY method is to
use dishwashing tablets, as they have a caustic effect.