Two different jobs get called gutter cleaning, and it is worth knowing which one you are asking for.
Clearing is the inside: getting the leaves, shingle grit and nesting material out so water runs to the downspout instead of over the front edge. That is the one that protects the fascia and the foundation.
Brightening is the outside: those vertical black stripes down the face of the gutter, which are an oxidised film rather than dirt and do not come off with a rinse. It needs treating, and it makes more visual difference to the front of a house than most people expect.
Gutters are the obvious thing to do while the house is being washed, because the access is already set up. Priced per linear foot either way, and doing both at once means one visit rather than two.
Prices are on screen in the estimator, and nothing is due until the work is finished. Book the date yourself when you are ready.