If you are already in VDO.Ninja, you can switch between your webcam and the virtual camera and normal camera in the settings. If you're a director of a room in VDO.Ninja, you can even share you audio and video from OBS into a room and not have it show up in any scene; just have it been seen by guests.
It is important to remember that you need to select the VB-Audio Virtual Cable in the call as well, if you also want to share the audio from it that is.
If publishing to VDO.Ninja, remember that you can select multiple audio sources in VDO.Ninja by holding down CTRL (or command) when selecting them. You could include the VB Audio Cable and your local microphone together, for example.