To me one pass is the first stroke up ( to remove dry soil particulate as the vac slot leads, and then quickly followed by a steam stroke, because the second stroke backwards in the same path as the upward path, with the steam off - only vacuum you are getting a dry vacuum stroke up, and a wet one back - for a total of 2 vac strokes.
This is straight up and straight back, and then over 100% for the next cleaning/vacuum/vacuum stroke.
Sorry no V pattern here, but will work for CGD, and depending upon your truckmount/ETM heat as far as being on the upper end, you can also kill some cut or level loop residential carpets.