Hold the jeans outside or over a trashcan. Place your hand inside the pocket, and spread out your fingers slightly.
Brush the surface of the pocket with the scrub brush. Use short, swift, downward strokes to remove the glitter.
Turn the pocket inside out, if possible. Brush off the pocket lining with the scrub brush. If you plan to wash the jeans, don't tuck in the pockets. For other pockets, like back "patch" style pockets, wrap masking tape, sticky-side out, around one finger. Brush the inside of the pocket with the tape.
Wash the jeans in cold water with regular detergent. Dry in the dryer as normal.