The military equivalent of WD40 is PX24. When I was serving on Wessex the Royal Navy used to wash and WD40 their Wessex both externally and internally every 28 days if I remember correctly. They used WD40 on them and not PX24 which I always thought was odd. WD 40 I was told stood for Water Dispersant ( effective for ) 40 days after which it attracts moisture, hence the Navies regime. I treat our aircraft with ACF 50 although we do not fly in a marine environment, damned good stuff.
As for washing, just look at the Nimrods, they used to taxy through a fresh water washing bay after they landed.. This is a P3 Orion going through a US one when taxying in.
http://www.navair.navy.mil/index.cfm...&gallery_id=48