Seeing invites for office hours or open mic discussions where those interested can learn about the organization. That is equivalent to hosting a career fair but not holding interviews to fill a job.
If this is too overwhelming for selection reps and job owners then maybe think about not having a system where you have to open and fill thousands of jobs at once. It is sad that we would be treated with more respect and concern as external job seekers not to mention they would make better decisions with external candidates and look at background and not who they like to hang out with on the weekends.
By the same token, the only thing I can say is that talking to job owners and selection reps is futile seeing as they will pick whoever they want even if he or she didn’t even apply for the job.