I bought a wave soldering machine some years back from a large local electronics company - when I picked it up, they gave me a tour, and they were using regular dishwashers for cleaning PCB's, along with regular dishwashing detergent. They said the boards were just as clean or more than using the special chemical mixtures.
They were using commercial dishwashers because they ran them non-stop all day long, but the boards were beautiful when they came out.