I have an IC and usually just manually stir the wort. I used my march pump to simply recirc (no whirlpool) the wort out the valve and back over the top into the kettle. My wort was down to 80 so fast I thought my thermometer was broken! It couldn't have been more than 10 mins, TOPS. Stirring worked pretty well too, but I highly recommend the pump. Also, if you use an IC, it helps to remove it when cooling is complete and do a strong whirlpool with nothing in the kettle. Let it sit for 15 mins, and you should have a nice cone of trub/break.