Hey,
Well, I don't really like using an xjet because you have to carry the bucket. I use a longe distance soap tip which can get up to that 35 ft peak you were mentioning. I have a hot water unit so it cleans a bit better than cold water obviously, but I think generally bleach works the easiest. If I'm not mistaken, the general mantra around here is volume over pressure, always. As long as you bleach thoroughly, and rinse even more thoroughly, you should be able to clean very quickly. For instance, I use 12.5% sodium hypochlorite, diluted about one half with dawn tossed in for suds and to add cling time. By the time I've soaped the entire house it's ready to rinse. I use my soaping tip for rinsing and just pull the chemical injector out of the bleach. After I purge the line the house gets a good bath. I did a 3500 square foot house in an hour fifteen using this method and it looked great. This method works well with cold water machines too, it just takes a little more chem sometimes and attention to the gutters I find. Since you don't like bleach, I'm not really sure what to say other than, I used to not agree with it either, but I've found that if you take necessary precautions, it's downright easy to not harm plants. By the time the bleach hits the house, it's below 1% which usually isn't enough to do any serious damage (if my math is right). It would be one thing if you wanted to x-jet straight 12.5% up there (hitting at about 6%). Plants would die everywhere. May I ask what you use for your soap currently?