We all know that we should stock candles and flashlights in the house in case of an emergency. But here's another idea for an emergency light-source that most houses have: Crayons!
Lately, there's been an influx of products on the store shelves that advertise that they can clean the leftover soap scum out of your washing machine and also remove the (sometimes) musty/sour smell. Most are priced around $10 a bottle and according to various reviews I've read - work with scattered results.