Several things to be aware of:
They can get into that locker while you are in the room for an hour. It is not secure. And obviously they have the master lock that opens every locker.
The times I was there I did not use proper judgement. Reflected upon it as a lapse of judgement.
The first time I was there, she asked for my phone, took it and placed it in the locker. Big deal, I have the "key." When I was completed, she took my key while I was in the room and got my coat and phone, she brought them into the room for me, and than walked me out.
The second time I was there, I did not have a coat, she took the phone from me while I was in the room. Same thing, when completed, she returned my phone and walked me out. Never went to the locker.
The last time I was there I did not go in with the phone. I am not sure I am comfortable with that either.