Is there a specific method you must follow to send entangled particles on their merry ways (in opposite directions)? For example, can you just shoot a lengthy and concentrated beam of entangled particles into open space while their partners remain locked in a box here on Earth?

 

Then later on, you interact with the particles from the box to affect their distant partners.

In principle, yes, if you can trap the particle without affecting the entangled state. You could trap a spin-entangled electron in a magnetic trap, for example.