How To Clean The Outside Of A Trailer I Have An Older Model Aluminum Travel Trailer,what Do I Use To Clean The Alum. With?

I have an older model aluminum travel trailer,what do i use to clean the alum. with? - how to clean the outside of a trailer

As far as I know, has never been cleaned. I am disabled, therefore you need is the best detergent I use that will bring her "beauty without killing my back and hips to know.