I just talked to my FH about this subject. He went to a catholic grade school and high school. In grade school, Reconciliation was made during an assembly, once a month (usually the first monday of the month). All the priests from the parish would be on hand to hear confessions, and they’d go by homeroom. Once in high school, they were expected to decide when they needed to receive the sacrament, so they were able to sign up for it in the school chapel in the morning, and the priest would call them out of class to hear their confession. They could avail themselves of this privilege as often as necessary, which my FH said was a godsend for dealing with puberty and the related urges as a teenager. He didn’t have to tell his mother he was going to confession, and he could go as often as he needed.