Never let a four year old play with glitter. Ever.
My niece got a hold of a bottle of glitter and dumped the WHOLE thing on her head. Her scalp is glittering green. They slept over last night and as soon as she got into bed she starting getting itchy- thanks to the glitter that was now all over everything. We tried to rinse it out in the sink- who knew glitter is impervious to water. So her scalp stayed green and itchy for the night. This morning I had the bright idea to use a toothbrush to rub the glitter out of her scalp (I used a new toothbrush). Well the toothbrush worked much better than the water but it also flung glitter everywhere. Bella is covered with glitter (even more than before), I'm covered with glitter, the chair is covered with glitter, the floor is covered in glitter, the dogs (all three of them) have tracked through the glitter and they are all now covered (lightly) with glitter.
Seriously people- stay far away from glitter!