I'm sure someone has posted some like this before but I came across it online.
It's a carboy stirrer made from a long plastic dowel that fits into a power drill (great for removing co2 prior to bottling or general mixing). You take one end of the dowel place it in boiling water and then hammer it into a paddle shape using a mallet. Other end goes into a power drill... Et voila! A cheap alternative to the $20 wine agitators.