whats the point? how does it feel? what kinds of things can you do with it (sex games and what not)?
The point is that you are surrendering control of your orgasms and sex life to your partner who will then determine when and if you should be permitted to enjoy an orgasm and how it should be administered.
This, however, does not mean that your partner will be going without sexual pleasure, as you will be required to give them pleasure in ways that do not require permitting you to enjoy an orgasm yourself.
This creates a heightened awareness of your sexual desire and generally results in you becoming more submissive and attentive to your partner's desires in the hopes of pleasing them enough to earn" your own orgasm.
All of this is really nonsense because it is just a jerk off fantasy game. Most of the devices are incapable of actually preventing you from escaping it or figuring out a way to achieve orgasm.The few that might are extremely expensive and require having your penis pierced in order to place a locking device through it.
Most "submissive" men that convince their partners to play this game as if it is a real form of submission, usually end up driving them crazy with all their whining and demanding attention.
True submission is surrendering yourself to your partner and controlling yourself for their pleasure.
So essentially chastity using the various devices is a game which can be fun for both partners if they both really enjoy playing extreme tease and denial sex games, but understand and approach it as a fun game and not as true D/s.