ᐅ Removing efflorescence and cement residue from the exterior walls

On the windward side of my house, unattractive cement residue and efflorescence have developed on the cladding after 10 years. On the north side, there are several white spots around the base of the wall. I tried cleaning the facade, but it did not work at all on the windward side. At the hardware store, they recommended using hydrochloric acid for cleaning. However, that seems too harsh to me, and I definitely don’t want to damage the facade.

Does anyone have any ideas on how to gently remove the efflorescence and cement residue?

There are cement residue removers based on hydrochloric acid. These work well to remove efflorescence. You should be able to find such a cement residue remover at a well-stocked hardware store. I do not recommend buying hydrochloric acid and diluting it yourself.