I've not heard great things with keeping shrimp in those long term, however short term it works well (so I hear) for placing a valued male and female together. The goal here to berry the fem.
Once berried you remove the male and have two options. 1) release the shrimplets into the breeder box, or 2) release the fem and have her release the shrimplets into the tank.
Both have pros and cons. However I think once she berries up, the best bet for survival of shrimplets and better care would be to release the fem into the tank.
I'm rapidly running out of space and may have to start doing this method myself, so I am following other threads on this as I speak.
---
These are simple ways to selectively breed. There are much more complicated ways such as doing multiple pairings, 1 male to multiple fems per tank, writing down shrimplet counts and results, and following family lines. However that takes lots of time and money and space. Keep it simple, keep it fun, and keep it a hobby that is relaxing. IMHO that is the way to be successful.