We use a chemical called ARKLONE (specifically ARKLONE-L) manufactured by ICI. The boards are then blow-dried by compressed air.

ARKONE-L has a very low boiling point, and at room temperature, you can see 4 inches (10 cm) of heavy vapour floating on top of the liquid in the tank (a lid is a must otherwise you end up on a permanent 'High' wading in the stuff!) if you put your hand in it, it'll be soaking wet long before it ever touches the liquid. As a by-product, if you stab a hot soldering iron into the vapour (c'mon there isn't an engineer on the face of the planet that doesn't play!), has a habit of forming cyanide gas which is great for getting rid of people you don't like... (always wondered why the Hells Angel types want to work in that department).