I only belong to two of their groups and I am trying to remember, but I would just tell them to dump whatever is there when they get back. I belong to several groups for which the administrators have made a "do not submit" request for a period, usually because they were going to be traveling. When they get back, they just delete everything that's been submitted anyway. I'm not sure how long it takes to do this, but certainly much less time than it would take to "process" all the entries. If you have submitted an image to a group and an administrator "rejects" it (which is what I'm suggesting here), you can still resubmit. You just need to go to the image in your own member center and then to edit. Remove the check-mark for the group and submit. Now the image can be resubmitted to the same group if you think it's a perfect fit.