I have a Tudor-style house, built in 1976, with real stone and wood, not synthetic, and I don't think the stucco is EIFS. The stone is getting a little grungy and I'd like to clean it.
I don't want to get moisture behind the surface. There are pretty wide mortar areas between stones. I have found that hand-washing, no matter what chemical I use, is not very effective. The abrasive effect of the power washer is what cleans my stone patio and walkways. I have an electric one with 1800 psi.