Product to clean interior softwall on Outfitter Camper

I have used "Reliable super spray cleaner" made by Reliable Products Oneida, NY. Sprayed on, then soft bristle brush, then warm water, etc. takes a lot off, but it never looks as white as new. This is an alkaline solution. I notice the previous poster uses vinegar, which is acid. Using these two, one after the other, might well be the best answer.