There was noticeably less reminding on my part to use lips only, no tongue protrusion, when drinking. I had ordered two extra #5 straws, anticipating Matthew to be on straw #5 for at least a couple months. Since he uses the straw for most, if not all, his drinks including water, orange juice, apple juice, and chocolate almond milk everyday, residue build-up in the straw was expected no matter how well it was rinsed through after every use. I also sent a straw to his preschool for him to drink with at snack time.
He was on straw #5 for almost 3 months. He "graduated" to straw #6 during the Christmas break.