Posting a sign that says RESTROOMS FOR CUSTOMERS ONLY might get the point across, but it’s not the most subtle method of communication. At ’wichcraft, Tom Colicchio’s sandwich chainlet, management has come up with something better, or at least more high tech. To ensure that the facilities remain the privilege of paying customers (not to mention remarkably clean), they can’t be accessed until you actually buy something. That’s because a changeable four-digit Bathroom Access Code is printed out on the receipt. Why go to such 007-level lengths? I don’t want people to think of this as aggressive or inhospitable, says chef Sisha Ortuzar, who’s implemented the combination-lock system only at ’wichcraft’s Greenwich Village branch, a particularly heavily trafficked location and one that was starting to become unceremoniously regarded as personal rest stop and occasional improvisational shower spot by passing locals. The new system is certainly a step up from being handed a giant block of wood or a five-pound dumbbell attached to a key, as is the coffee-shop custom. No one wants to touch that; you have no idea where it’s been, says Ortuzar. On second thought, you have a pretty good idea.