I took at least 20 minutes off my cooling time when I added a stand pipe & hose to my ice bath to drain the hot water sitting on top of the bath.
Get a rubber stopper and a length of PVC pipe from Home Depot, etc.. Punch a hole in the stopper and glue it to the PVC pipe to make a stand pipe that fits over the sink drain. Cut the PVC pipe to the height you want the water to be in your ice bath when you are cooling your brew pot.
1. Run a hose to the bottom of your sink/tub (mine comes from the faucet on my garage sink, the wrench is to weight the end down. Also ignore the black tube in the sink on the left, that goes to the washer).
2. Plug sink drain with stand pipe and fill the sink with ice water, add brew pot.
3. Keep the water running slowly from the hose. This pushes the hot water into the drain, keeping the overall bath temperature much cooler.