In between uses, this mist can be used to refresh your brushes. Simply mist, swirl onto a clean towel, and let dry.

However...
You should wash all your brushes on a weekly basis. That may seem like overkill, but your skin will thank you. The makeup also applies better with freshly washed brushes. And if you don't wash your brushes, it can ruin them. All you need is a little shampoo and running warm water. Rinse the bristles under the warm water, swirl your brush in some shampoo in the palm of your hand. Continue swirling your brush in the palm of your hand under running water until the water runs clear. Gently squeeze the water out of the brush bristles, lay the brushes flat to dry, and try your best not to get water into the shaft of the brush.