I like this idea.
I have a suggestion. It's a bit complicated I'm afraid, but definitely within the capabilities of some of the people on this site. First of all, to overcome Blacky's problem, the cage would need to be closed before anything could be done inside it. This would require some sort of proximity detector on the door to check that it is closed. That way, the cage could be quite small and restrictive. There would be a mag lock to lock it. Inside, there would be some equipment to allow you to perform some sort of task, which could not be performed from outside, say push a series of buttons in the right order. All this would be connected to a safe containing a control computer such as an Arduino, Raspberry Pi or similar. Get the task right and you're free, get it wrong and, click, you're locked up. Maybe the lock up time could depend on how well you do rather than just succeed or fail.
You might want to leave it at that, but the control computer could be programmed so that you have to go into the cage at pre-determined times and perform the task. It might be just once, say when you get home from work that evening or it could require the task to be performed many times over days, weeks or even months. Get enough of it right and the safe can be opened.
As an example of how it might be used, suppose you wanted to learn a language. You would prepare a number of lists of words to learn and enter them into the computer. Each day you would have to go into the cage and be tested on one of the lists. Get it right and you would be let out, get it wrong and you would be locked in for an hour to mug up before another test. Get this one wrong and it's another 2 hours. You'd have to be let out eventually, but the computer need not forget that you failed the test and let you off.
Now you would need some sort of incentive to make sure you go through with this. Often, when I go shopping, particularly for clothes, I know that some of them will turn out to be no good and have to go back. There is usually a time limit to return them. You do the same thing but, instead of returning the items straight away, you lock the receipts in the safe along with the control computer. Perform well enough in the tests and you get the receipts in time to return the goods, fail and you will probably have spent a long time in the cage
and be giving away some nice new clothes
.
Alternatively you could put the key to your chastity device in the safe. Fail and you spend more time in a cage and in a cage.
With a scenario like this, you would be the victim of your own cruelty, not just for a few hours, but for days or weeks. Also, it might help you do something really useful.
It would need to be cheat proof. All the cables connecting the cage equipment to the control computer would have anti tamper wires included. If you tried to interfere with any of it you risk cutting those wires and losing access to the safe immediately. Any communication between the control computer and another computer would need to be encrypted, so that you could not program another control computer to pretend to be the real one.
Of course, suitable safety backups would be essential.
Any thoughts. Is it too elaborate to be practical?