I have an MV brand (?) gun that came with my craftsman pw. I want to put a qc on the discharge. Currently, the discharge is (appears to be) bolted brass nut 4 sided to the barrell , which in turn is connected to the wand. Can I undo this nut and replace it with a qc so I can easily switch between pw and surface cleaner? It appears threaded and I think I even saw a bit of liquid (oil ? ) coming out of it?