IMHO, DON'T use the glass. There WILL be glass dust created. Unless you know 'clean shop' procedures and are set up to handle your cleaned brass that way and only that way, you are handling very harmful to your health items.

It is possible with good vibratory tumblers and media from walnut shells, corn cobs or stainless steel to get as good of a cleaning job as is necessary without risking your health. ....