They are great for a pre-wash soak to avoid any chances of marring/spider webbing your paintwork. Realistically no, it is not a touchless wash. Consider this, you're in the mud all day. You snow foam yourself, you rinse yourself. Are you clean? There is your answer right there! And if you answered yes, than i am worried!
Awesome thing, and lots of fun. But how well do you look after your car now? Do you use a two bucket method, a soft wash mitt? microfibre chamois or waffle weave? (NOT a chamois).
My answer is yes worthwhile.. but thats up to you if it suits.