Changing the owner of the Stream is usually the way I go about "hiding" a Stream.
Instead of putting the project area or a team as owner of the Stream, I put myself.
Putting, as you mention, a "Team Area of one" is another option.
This is part of the RTC3.0.1 release, which does have "permissions to control access to streams", and not only set the ownership on the stream, but also on the component, and restrict said component to the team owning the stream:
Make the component private by selecting Flux Capacitor 2 and clicking on the Change Owner button.
In the ownership dialog, expand JUnit Project and select Flux Capacitor Tiger Team.
Visibility is limited by checking the Restrict to members of this team area and its child team areas, as shown in Figure 10