Need to exlcude campaign members.. any ideas?

We are running a campaign for which we want the campaign members to be excluded from all other communications except for a couple significant communications. 

We have multiple workspaces and this particular program is built is the US workspace – so the default workspace cannot access any campaigns or programs form the US workspace. So the global campaigns that our teams run, we figured that excluding this particular program by the SFDC campaign, would be a good option. Does anyone know or have thoughts  if there is anything else I should do to ensure these leads/contacts are excluded.  Would a list work better for the US campaigns?

Thanks!