I cleaned the outside then took a deep breath and said what the hell and went in with the pressure washer, it was like being in a Maytag washer:banana
When I got the rig home i tore out the fridge the heater and stove. I am going to fill in the fridge hole put the new fridge where the heater was install a toilet etc etc.
I am probably going to rip out the liner clean the interior fiberglass and spray it with a Rhino liner in light grey with ceramic insulating beads to replace the neoprene/vinyl liner, first I will do some expirements to determine its R factor and if it can be sprayed.