My wife complained that a lot of the public bathrooms she goes into have broken locks, so she is forced to hold the door closed with one hand while trying to do her business. I look at the stalls where I work, took some measurements and came up with this device. The original design I came up with didn't fold, but my wife said it was too big to put in her purse, so I cut it in half and hinged it.
The two parts should be printed separately to reduce the size of the Purge Wall when printing the one with the inset words. You will probably have to position the words yourself in the cutouts. Use supports, but a Raft isn't necessary if you keep the build platform hot enough. Once printed clean up the parts, snap together and you are ready to use. Just open it up and position it on the door and slide until it engages the door frame or post.