Like I said it’s been a long time since I dove with a double hose and I don’t remember if it was clockwise or counter .
You want to do a slow roll that will move the water in the hose to the exhaust port and you should be chest up toward the surface which would put the water at the lowest point in the loop so it can be blown out.
You could add a valve from a rebreather so water didn’t get into the hose but then it wouldn’t be vintage gear :)