our alu floor one goes down the local hand car wash in the village for £15 to do the outside soap and pressure wash. they would do the inside if wanted too
tend to do it on a nice day so drys out quick, wasn't happy doing it with the old richardson though, didnt dry out v well!
On my Ifor 505, I do the white bits with Cif multi-purpose antibacterial spray (it has to be the antibacterial one, the others don't work as well) to get the staining off with just a cotton dishcloth. That and a pressure washer.
I use flash spray with bleach on the inside just in the hope it might keep mould/mildew from forming.
Jet wash to remove all stubborn green mossy bits, wash with hot water and car shampoo and if your really energetic, polish with car polish. Helps the rain run off it and keeps it cleaner for longer. Inside just hot soapy water with or without car shampoo. Jet wash floor and leave open to dry in sun.