More secure than keys—you can't remote-wipe keys. (And, presuming the network requires a password, remote-wiping the phone would make it not join the network any more.)

Re-keying the locks is kind of like remote wiping all the keys at once. Certainly not as fine grained, but will work in a pinch.

You could also edit the home automation script or block the phone on the router if remote wipe isn't an option.