This month, as I have for the last 25-30 years, I have to clean a little over 800 stack chairs in a large banquet room. They look like this; front, back bottoms upholstered.
I've tried various procedures; cleaning them where they sit usually around long tables, lining them up in a semicircle stacked 12 up and 15 around, doing the job by myself or with one or two guys helping. By myself I usually go 60 per hour and it takes two hard days. With a helper about 1 1/2 days (at 80-100/hr) and with 3 guys, one long hard day. I will probably have to do them myself as I have run out of people willing to do this job because it is so hard.
Economy of motion becomes the default choice. I will most likely just clean one stack at a time, cleaning and restacking and moving them back into their place with a hand cart.
My favorite tool these past few decades is the internal jet PMF set to continuous flow which follows a misting of prespray and, usually, a scrubbing with various sized tools as needed.
Last year I tried using the Rotovac upholstery tool but after a few chairs there was water overspray all the **** over the floor and my pants and shoes and I had to put it away.
I will try my
Sapphire UpholsteryPro tool set to continuous flow this year and hopefully that will be the new favorite. I have two so if I can get help we can use matching tools and work simultaneously and maybe crank at 100/hr and finish in one day. (Of course going at this speed is why I lose them).