Me too on using soap tip to rinse with. You can use a weak mixture of alum brightener like used on tanks for semi trucks to get the stain off if you do have some run out of the weep holes and it dries and leaves a stain. Been a lil trick of mine for years. We have a LOT of what we call dirt dobbers (kinda like a wasp but builds nest out of dirt) and its practically impossible to keep from getting runout like your pic around here unless its a house that is kept sprayed by exterminator or something to keep the dirt dobbers and other pests ran off. Also maybe we have crappy siding installers or something around my area but with 8gpm I can't keep from getting runout on a really dirty house. Don't know about your area but houses get DIRTY around here before they are cleaned!! Lol. Most of my customers call me back but no matter how many reminders I send, most wait till their houses are really dirty before they clean em again.