Pond pump.
Get 3 - 5 gallon buckets
Put pond pump in one bucket and fill with tap water
Fill second bucket with water, leaving room for 5-10lb ice, but don't put it in until the last minute to save all the therms
Leave third bucket empty.
Hook pond pump to chiller, output to empty bucket. Hot water for clean up
When pond pump starts sucking air, stop it
Fill pond pump bucket with ice, and water from third bucket
Put output into TOP of ice bucket for recirculation
Turn on pump again
Most important during all of this and something not shown in the video above -- stand there and swirl and raise and lower and swish that coil around CONSTANTLY.