Ignoring the obvious question of why you want to put everything in your archiving system on hold, Can you not just run a search without To or From or @. As long as the archives for FSA are selected, this should do a blanket search. Assuming it is setup to search your FSA archives.
The only constraints then would be your envionment and whether it would cope doing such a search. There is a limit to how many you can put on hold at once I think which can be changed by a DA config home page.
So knowing nothing about your system, you should be able to create a case that will search all archives and put everything on hold by doing a blank search.
The caveat is that it depends on how you system is setup, hardware and envrionemnt as to whether it is going to crash other functions of EV and DA.