From my experiences in the classroom, if you desire to see how a teacher is doing, you can ask the custodian.
Students that care about their learning usually care about their learning environment; And if a teacher cares about the learning environment, a procedure for students should be in place to maintain its status of CLEAN. Teacher Created Tips blog has some great ideas in keeping a tidy room.
All students deserve a comfortable, attractive, safe and CLEAN environment.
Remember, that EVERYTHING SPEAKS…