Cleaning your glass and crystal jewelry regularly will ensure that the beads glisten and refract the light as they did when you first made your necklace. For most of your glass and crystal bead jewelry all you need is to wipe using a damp cloth with a little dish soap. This will remove any dust or buildup on the surface of the beads without risking the problems that incur by immersing in water or cleaning solution, such as thread deterioration or cable rust that can stain the hole of the bead. If your beads are so dirty that this method does not work you should take the necklace apart, clean the beads and restring. Do not use commercial dips as they will remove any coating that may be on the beads.

source:https://www.beadmecca.com/content.php?page=Jewelrycare