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