Cleaning stucco with Borax
Not magic, not a mystic secret, but Borax helps a lot in cleaning stucco.
I got a box of 20 mule team Borax from Amazon. You can also find Borax in some grocery stores. I remember 20 mule team Borax commercials when I was a kid. These days, driving a mule team through the desert would be considered cruelty to animals, and rightfully so. In the late 1800's, they couldn't make a train that would withstand the desert heat, so they used mules to transport the Borax from the mine. Borax was discovered in 800 A.D. in Tibet.
We mixed the Borax one scoop to a gallon of water. 4 gallons did this whole wall. The truth is, Borax isn't a magic fix, but helps a lot in removing mildew and stains. What did the cleaning was this plastic brush, a hose, and scrub, scrub, scrub. I got a pole to screw on the brush, too.
After the first wash, the mildew spots were sprayed with a garden pump, and then washed with a hose. Nearly all the mildew came off. We stuccoed this house in 2009. It was an EIFS tear off. These color cement finishes are sensitive, and the Borax didn't affect the color. We cleaned another addition we did about 10 years ago also with good results. Borax works good also for killing black mold. We usually use bleach. Bleach is really caustic, and smells to high heaven. Using bleach on a color cement finish can mess up the color, where Borax won't.