The Revenge of the Hot Water Bottle
Also discussed here:<p><a href="https://news.ycombinator.com/item?id=30024127" rel="nofollow">https://news.ycombinator.com/item?id=30024127</a><p>We now use "Wheat Bags" ... cloth bags, usually cylindrical, filled with wheat.  Heat in a microwave and use where one would use a hot-water bottle, but without the danger of a leak.