Really the only thing blocking things like this from existing en mass would be the expense in crafting them.
The concept of the behavior enforcing item can be used widely, and this is a decent version.
In many medieval settings, I don't see this device replacing the headsman's axe or other corporal punishments except for overtly 'enlightened' societies. The rich might get collars, the riff-raff get the axe and the rope.
In the middle of an unimportant combat with some bandits a burst of wild magic transforms all of the PCs and their opponents in to random animals and monsters. They retain their intelligence (though not, of course, the ability of speech). They can either carry on the combat in their new forms, panic, or otherwise react how they see best. After about an hour, they return, unharmed, to their normal form.