Washing during drought

So, we recently moved to central california...(military, we had no choice).
We have a 40' toyhauler, and it despretley needs a bath. However, with the current water shortage, and price we pay for our water bill, the trailer isn't getting the bath it needs. So, doing some online searching, I found this....anyone else using it? What are your thoughts? For those other Cali folks, what are you doing to keep your home on wheels clean?

Waterless Wash Wax All