OP is just one more way to Very Low Moisture a commercial carpet.
Out of all the VLM systems it actually removes the most soil if you do it properly.
You need an OP type machine (look for the Hruby Banner here) lots of cotton blend pads, some synthetic pads for lite soils, loads of magic pixie powder juice (Snake Oil is the flavor of the month) a few spotting agents, a '82 Dodge Omni hatchback and coffee can full of quarters for the laundry mat.