Whatever works, but I have a background in cleaning aviation fuel tanks. I am familiar with Leo/Uel etc. personally I wouldn’t do it the way you did. I would prefer an inert gas like nitrogen or even just and air compressor if I couldn’t run the water.Bottom line. My method worked. It took about 4 hours to find the leak, open the stud bay, fix it and patch & tape the wall.
I'll take those results any day.
This is a place for professional plumbers to shoot the breeze and trade tips etc. you do you and whatever keeps the food on your table.