Inside the bead hole is bead release that allows the bead to slide of the mandrel that all glass beads are made on. Some of the component in this mixture are kaolin which is a clay, nepheline syenite sort of flux, alumna hydrate and diatomaceous earth.
These element of dust are airborne / released onto the air when cleaning. So I recomend you clean the beads in water. Also if you have sensitive skin it is best to wear gloves as the components can dry your skin.
I have cleaned beads buy soaking in diet coke and or vinegar which does remove the bead release easier and then use a pipe cleaner. I have read you can cleaned in steradent denture powder and warm water.
I have used a bead cleaning tool, as photo. The other thing in the photo that I made that does work also. Is using fine wire to wrap it around and around like a coil over its self. Just like the pipe cleaner buy pulling back and forth in the bead hole to remove the bead release.