Negative Chastity

I'm referring to chastity devices that push the penis back toward the abdomen so that it seems to disappear. Invert or negative chastity devices. They look simple and severe. Anyone tried one? A regular cage is intense but these seem even more so...

I have tried one. My dick would not let it go on, but I'm going to try it again. Guess I have to stay locked a lot longer.

At times when my wife has insisted, she has only used a cage at allowed about 6" of flaccid cock. It's enough to allow me to wee. Does the job she requires which is the main thing. Single use is to prevent missuse by the SIL. She was caught once but that's another tail to tell.