I've used homemade ice with good effect. Either boil the water and freeze it the day before, or use water straight from a sealed water jug. Either way, santize the container you freeze it in.
Also, break up the ice before you add it to the kettle. 1 pound of crushed ice cools a lot quicker than a 1 pound block that floats around for 20 min before it melts all the way.
But do yourself a favor and go either the No-Chill route, or get a good immersion chiller and a submersible pump. Both ways are superior to using ice baths, imho.