Our 40 footer has been trashed in the last two weeks. We washed in from the West into Texas now and the grime was amazing. Two inches of standing water out of our rv entrance at one time.
I use about three buckets of warm water and soft brushes to rinse off the MH from eye level to the bottom. I can get it looking decent in about 30 minutes. When possible and it needs it I do a touch up wax and twice a year a full wax job with a great buffer.
When I do the bucket wash it is early in the AM or just before dark.