How to Get Rid of Mobile Phones

I've had this in my school where you don't think they'll work, but actually they work absolutely perfectly. So our mobile phone policy is that students enter the classroom, put their mobile phone in a pouch that's on the wall and take a card out of that pouch, then put the card on their desk. About three days in, every single student is doing it without question. It's a habit. And again, they do it in every classroom everywhere in the school because that's a site wide expectation. They themselves have self-regulated around not crushing the patches at the start of the lesson. Just doing that set of behavior around the door that allows them to put their phone away