i have done alot of this
i just use wfp and rinse. power washer is good to wash down, but the rinse from the pole is enough.
if its really bad i use a product called "orange" its a heavy degreasant. ive yet to use tfr, but i imagine it does the same job. i just get a pump action weed sprayer and pre soak then pole off
how dirty are they? whats on the cladding?