You can do that by setting up your Receive Shape / Receive Port inside the Orchestration as Direct Binding to the Message Box. That’s really what’s going on under the covers anyways
You can then subscribe to anything you want using a filer inside the Orchestration. You can subscribe to something like MessageType.
Now, use caution. It’s very easy to get into an endless loop since when your Orchestrations Sends a message out it can also get picked back up again by the receive (if the properties match).
I’ll sometimes create a custom property that I set inside a custom pipeline called Process. I’ll set it to false in the pipeline and true once I hit the Orchestration. Might be something else that Biztalk gives you that you can use like ReceivePortId Exists or something like that. In any case, if you see cpu hit 100% you know your in a loop.
Best of luck.