Waterless are ok providing there has been some prior prep done ie is the paint waxed. Personally if I had no other choice I'd go the local petrol station give the car a good jet wash off drive it home so its dry and then use one of these.
I've got countless ones in my garage but I only ever use them after I've washed and dried mine properly as some of them have great ingredients.
All depends on you, a red car may show up so e swirls if you don't get it right so just be careful I guess.