It seems that there's no way to lock the divine chastity belt&bra so they can be removed by the shopkeeper.
Meanwhile the shopkeeper can't remove some restraints with lower lock level, such as Fuuka's collar or dollmaker's visor, and the description of heavenly&divine restraints says that "only a Goddess' will can release you". It's a little bit weird, and perhaps the divine&heavenly restraints should be automatically locked while equipped?