[header] How to clean crystal [title] Ensure your crystal is dishwasher safe. [step] Many crystal glasses have a dishwasher safe label. If yours do not, check with the manufacturer or research online to find out if they can be put in the dishwasher. 
Crystal manufacturer riedel notes that their glasses are used in hotels around the world and are thus cleaned in professional dishwashers. If you cannot find any information, err on the side of caution and wash by hand.