OK, old man story here (I swore I'd never be this guy...):
Back in the late 70s to early 80s, cleaners just could accept spending 8-10K on a truck mount.
As a traveling truck mount salesman then, the right thing to do was to focus on production time and performance, which is why I spent my late teens through early 30s cleaning restaurants for free after they closed from New England to the Carolinas to Michigan.
But the other thing we did was try to show people all of the other cool things a truck mount did, so that the guy could justify the costs:
My demonstrations included:
Climbing up on ladders and using the high pressure hot water to melt ice out of gutters ( I learned to hate this)
Pressure washing siding and brick. (Guess what? Many brick and masonry cleaners contain Hydrofluoric Acid....which etches glass. Glass windows.... Paid dearly for those)
Steam cleaning engines. (I found out about protecting electric components from moisture...after the first one I did)
Pressure washing heavy equipment (Yes Nick, I removed decals too!)
What is funny is that at that time, no one thought of using the truck mount for hard surfaces and upholstery, as we commonly do now.
Oh, one more thing:
All of us truck mount salesmen heard a story (probably apocryphal) about about a farmer who pressure washed pigs before they went to the slaughterhouse.
Thank goodness no one asked me to demonstrate THAT one!