There are so many automotive wash soaps products available today it becomes difficult to find the best one for your RV. You want one that cleans well, takes as little an effort as possible, and hopefully eliminates the need for drying. Well, I found just that some years ago and still use it exclusively.
The product is Voom RV Cleaner and Degreaser. The name sounds like something you would hear on a late night infomercial. But I can assure you, it is far from a fly-by-night cleaning product. It is truly amazing.
It is generally sold by the gallon in a concentrated form. You merely pour about an inch or so into a bucket, (more if the vehicle is extremely dirty) fill the rest with water and you are set. Using a long handled brush, apply it to the surface. No rubbing, just brush it across the entire coach body doing only an area of 20 to 30 square feet at a time. Now rinse with water, washing all the soap off. That’s it! It will dry with what is as close to a spot free finish as you can get without special equipment. RV washing should always be spot-free.
I have used this with well water, city water, hard water and soft. The results are always great. I once washed a dirty black H2 Hummer in 10 minutes using well water. Once finished it looked like it had been waxed.
The manufacturer is in Georgia, and I have no connection or interest in the company. I use Voom RV Cleaner, the best RV wash product, not only for my rig, but on my cars too. I have found nothing that will come close to this product after over 10 years of using it. If you have never tried it, please do. I hope the results for you are as good as those I have found.