People misunderstand glitter. Treat it as a hazardous substance, not unlike a can of polyurethane, and generally you will have good results. Follow up by sealing it with polyurethane after for full effectiveness. It is not that it is not a child's toy, but that children miss half the experience, as they are not the ones getting glitter sealed to their skin with polyurethane for the better part of a week. They are fully capable of learning proper handling, and with this knowledge, nobody need deal with loose glitter ever again.