I have had numerous students ask the infamous question at least three times in a period. "Can I use the washroom?"... It seems they've been programmed to ask the question. They have that feeling of guilt without asking, so hence they must have permission. And when they do have permission and they wander in the hallways, they feel like criminals getting away with something mischievous.
The only reason these students are asking this question, is because they're bored in class. When they don't ask within the hour, that means you're doing something right in the classroom. That should light a lightbulb.
I just find it so entertaining the number of times that these students need to have an excuse to leave the classroom.
The system is flawed. We treat our classrooms as cages. If a student wants to get some fresh air.. then just go. It's a free world. It's a real world. In society, we don't ask to use the washroom. I think there needs to be a change in where and how our students learn. It needs to be more relaxed. Give students more responsibility. We can't continue being drill sergeants. The hallways can't always be empty at all times. Classrooms need to work together more. Noise is good.. it's not always bad.
Here's a test:
Ask them when they ask to leave the classroom, "Are you bored? Why?" Make a list of the reasons.