I have SWM and OTA diplexed at the entry point into my home. Each room of my home is wired for DirecTV and OTA with one cable run to the wall jack. At the wall jack, I then diplex out the DirecTV and OTA signal. This is how I did it:
Entry Point
SWM ---> Power Inserter ---> Diplexer (OTA and DirecTV) ---> DirecTV approved power passing splitter ---> Each room
Each Room
Wall plate ---> Diplexer (Only needed if you want DirecTV and OTA both. Not needed if you just want one or the other) ---> Receiver/Converter Box/TV