My boy is 5 months+, just wondering if its okay if I let him have the rusk biscuits? Those are hard ones but will soften up after a while. He also seem to be 'chewing' on his pacifier

Yes you may give to your baby the teething rusk. Avoid to let him chew if the rusk has became soften and refrain from giving him a short one as this might cause choking hazards. Do supervise closely and never leave him alone while taking the teething rusk. My both kids enjoy the biscuits very much when they were young.