I use Klean Wall too. Yes, it will etch tile and stain your stainless if you let it dry.
I used to mix it in a deck sprayer, but I've found I can get a lot more done with a lot less cleaner if I mix it 2:1 and brush it on the wall. It doesn't atomize and get all over me, and I can easily keep an 8' section wet until the buildup starts to break down, then it comes right off with the bay pressure.