The place where I live has a very old refridgerator. So old, that the freezer portion does not auto-defrost. It’s basically a box with aluminum walls and over time layers of ice build up. So we tossed what food we could and stowed the rest at Stone’s place. Then we got down to exploiting technology to turn a 24 hour process into 2 hours of work.
We looked online and many people recommended using rubbing alcohol in a spray bottle. Some said to try a hair dryer. The alcohol spray bottle actually helped to turn any loose ice into slush which we removed quickly. But, this method was not going to remove the solid ice very quickly. So we developed a two pronged approach that yeilded the best results. First, we turned the fridge off so that the appliance was not working against us. We aimed a fan at the freezer and boiled some water. Between the fan moving air through the freezer, setting the pot of boiling water in, and occasionally spraying alcohol onto the ice, things started to loosen up. The key seemed to be letting the pot of boiled water sit in the freezer till it was room temperature. Eventually there would be openings where a spatula would easily wedge a huge section of ice away from the wall. The fridge labels recommended 24 hour time for a full defrost and we had all the ice out in 2. Not too bad.