It works just fine. I went to an inn, found a chest with "Steal" above it.
I opened the console, clicked on it, typed setownership, hit enter. Looked away, and when I looked back, it no longer said "Steal".
If the wiki is to be believed, it is now my chest.
If no Owner is specified, the reference will be set to player ownership
Ok, so it's from the Construction Set wiki but they are one in the same.