I'm still doing kit brews and recipes that have at most 3 gallons of wort to chill. I use a ice and water bath with rock salt added. I have done this with my last two brews and it has worked very well. The last time I filled my sink with cold water and placed kettle in the water. Added one beer pale worth of ice and rock salt. Once this ice started to melt, I added a second pale. I'm guessing the cool down time to be 15 minutes. I did not stir the wort, just swirled the cold water around the kettle. I don't have any empirical proof the rock salt helps me, but if it helps to freeze ice cream it should depress the water temp to help cool the wort faster.