[quote=@6slyboy6]
[@Prince of Seraphs] Hmmm makes sense. But you can possibly get your hands on a ring or a sword SOMEHOW, and that would grant access to all the safehouses. A fatal flaw if I do say so myself
[/quote]

When these safe houses were first constructed the objects that granted access to them where only carried by Royal Guards or high ranking court officials. So if someone you didn't want in one of them has an object that grants access you have the much bigger problem of dead Royal Guards and Court officials. Nowadays for those that know of them it might be easier though still rare to get your hands on a seal to open one of the safe houses it would have been inconceivable during the time that the houses were actually in use.  Plus the King thought he had another fifty years to work through the problem of the demons so all the Royal Guards being slaughtered was no foreseen as a possibility.