Tell us about yourself!
My father in law is a retired pipefitter and gave me this tip when I was trying to replace an outdoor water hydrant. I had to cut a hole inside the interior wall and could not completely turn off the water. I had a slow drip. I called him he suggested either bread or mud. I have tried both over the years and have found both work. The bread or mud will flush out after the water is turned on. One just needs to block the flow for a few seconds while soldering.