Few problems .
1) most toilets before them have them things with alarms.
2) Security camera's are monitored all the time so they would most likely see you.
3) Don't run you look guilty they would suspect something.
4) Their are better ways to rob then this.
5) me and my friend used to rob from sainsburys we packed bags with shit loads of pick n mix (£14 worth xD). Then we went the toilets filled out pockets w/e then walked out casually. We eventually got caught on the 14th time robbing, we got banned for life from the store but i still go their .