Alright so from my experience they dont come into the classrooms, only lockers and the hallways. Also when they do search they close the doors so the dogs are not even able to get to me. But in other experiences dog= your fucked, try what b-rad said but me and my friends just do the saran wrap with 2 ziplock bags, so far i have been lucky but my friend does the same stuff as what you did minus the jelly and the dogs still got him.