I have an idea. Make it so that the only way for prisoners to get items is for them to actually go into restricted areas via vents that can only be opened with a crowbar. The crowbar is only found in the armory, meaning that players would have to try and find a loose crowbar, in very secret areas of the prison only accessible with those who are very experienced with the build/server or being forced to search the whole prison for it, like a secret hole in the walls. Such has a wall that secretly has collision off, like those high up ones. You can choose where to get these crowbars if you'd like.
EDIT: NO DONATOR LOUNGES