I glad to hear at least one other person is using dish soap as well. Among the items I do
not have in my not so well-stocked household: vodka, PGA, vinegar, baking soda, peroxide, denture tablets. Which I think covers everything suggested other than hot water (which I do have).
I'm assuming, but perhaps shouldn't, that dish soap would be a bad, bad, bad idea where the heads are concerned -- that it would gunk up the coils or wicks, or mess with the electrical or whatever. On the other hand -- urban legend perhaps, but I've heard that Dawn has been used successfully for de-gunking birds that have gotten life-threateningly stuck in oil spills. Well if it's that good for the poor little birdies...???