Since zc is not tradeable it is near impossible to get huge amounts. The only option is missions which give 4 zc every 5 minutes. Could staff please raise the zc amount from missions to 10 or something but make every 8 or 7 minutes.
I doubt this will be implemented since this server is in complete chaos but it's worth a try.
Back in 2015-2016 we would get the Med bots and go into the mission with a bunch of noob accounts, and when you had a lot make the noob account trade your main all the stuff. Unfortunatley this would be really hard now due to the removal of the med bots.
It could still be possible if you're really good and kill all the spies, but if one your noobs die youll get less zc. Worth a shot tho