Hi Sally and Bez,
With the MM devices, you have the option to order anti-pullout pins. They come in small, medium, and large and can have different ends (blunt, rough, etc). Bill will then make the device with a hole in it that you can put the pin in. I did get this for the Jailbird. Ab wore one pin (small, blunt) for a day or so but then asked me to take it out. He said it was annoying and felt like a pebble in his shoe. Atone, on the other hand, didn't have that problem. I think it's all a matter of what feels comfortable to you and some people like a little more discomfort. My husband isn't one of those people, however.
I find that both the JB and the WM are very secure. I don't think he could get out of them easily. But then again, he doesn't really try to. As many have said, a big part of chastity is what is between your ears. Ab has access to the key and only uses it on the schedule we have agreed to. For guys who want to get out of their devices, for whatever reason, is anything ever going to be totally secure? I don't think so.
D