I'm really interested so thanks for discussing!
Yeah, the milking thing is right, I read it on a chastity device website - it's important to get rid of the old sperm for health reasons, and regularly 'flush' out, but people who are doing intense orgasm denial will tend to do it this way, without orgasm.
It'd be great, Ruby, if you could pass on some more info from Nathaniel. Has any other male sub done this?! Please speak out!