Remove the ability to open one's house specifically to one's allegiance.
If one wishes to allow one's allegiance to use one's house, then one must open it to the general public. Otherwise, one is restricted to the limited /guest list.
I admit the idea came to me from the olthoi thread, but I decided that this is a separate enough issue to require its own thread, as it's not specific to olthoi play. This allows Dereth's private denizens with housing to set up trade bots et al, but prevents true allegiance housing from becoming a safe zone. It would also require trivial additional coding; simply remove the status and command.