Our Keg WaSsher was designed specifically for cleaning cornelius kegs that are commonly used by homebrewers. While it may be possible to adapt the Keg WaSsher to clean a carboy, it is not something the Keg WaSsher was intended for. With traditional "slim neck" carboys, it would be very difficult as you need room for both liquid drainage and for air to enter and leave the carboy, in addition to the CIP ball. Without this, an airlock may occur which could cause performance issues or possibly damage the carboy and/or Keg WaSsher. If you have a wide-neck carboy, like a Big Mouth bubbler, it may be easier but the Keg WaSsher is not designed to attach to a carboy in the same way it can a keg and it would likely be very unstable.