How do I transfer a Leader / Governor between different empires?

In the past I could select a specific ruler then use a console command 'effect exile_leader_as = [PutWhateverHere]' in one empire then selecting the correct job in a different empire (in this case a planet) use the command 'effect set_leader = [PutSameAsBefore]' and said ruler would now a governor in the new empire. This no longer works, while exiling leaders is fine adding them back to another empire doesn't work. Just getting 'effect executed' while nothing changes.

Does anyone know how to trade rulers (governors or scientist) between independent empires using console commands? Any help would be appreciated.