I gave up on the big local power washing company because it was getting too expensive, quality was suffering and charged extra for every little thing.
Had them annually (sometimes twice per year) for years. Vinyl sided house.
Tried "Wet and Forget" 3 years ago for the whole house and am pleased. Spray it on with garden hose and leave it. I do it once per year.
It works slowly and house looks great.
Link below
https://www.wetandforget.com/wet-and...-hose-end.html