I have to admit, I thought the idea of "Quiet Spray" may have seemed a bit juvenile for third graders. Boy was I wrong. Using an idea I found on Pinterest, I bought a dollar spray bottle and filled it halfway with water and glitter. I took the stray out so it wouldn't actually spray. Then I added a quick label, and it was ready to use.
I honestly forgot about the bottle the first 2 weeks of school. My class this year is awesome - except when getting in line. I was fed up one day and noticed the bottle on the desk. I told them I was spraying them with the Quiet Spray so they had to be quiet. They couldn't feel it because it came out of the bottle invisible. You could have heard a pin drop. I now use it almost every time we line up. The improvements are incredible and last into the hallway.
At the end of the day, I had my students line up but wasn't by my desk to use the quiet spray. I gave one warning about getting quiet. Then, a student asked about the spray. They now want it every time they are in line.