Great orgasm to watch and to hear. My first girlfriend used to love to see me lick her juices off of the brush, and also to spread her pussy lips after her orgasm and have me gently run the bristles over her clitty. This could make her cum a second time or get her aroused to bring herself off again with the handle thrusting furiously in and out of her cunt.
women do get sexually frustrated. Some women need it just as much as men and when they don't get it, they will do things to themselves in search of the feeling they crave. Hair brushes are very commonly used... the handles are usually just the right size. I actually think many brush designers consider this alternate use when they size and shape the handle.