Devin this has been fun. Great job on videoing this interaction.
So the most the current crop of VLM ---house cleaners---- use what is called Padcapping. They vaccum, prespray, agitate the prespray into the carpet and then go over the carpet with cotton/poly mixed pads to further agitate and absorb some of the dirt by going over the carpet with a rotary or ocsillating pad machine---their pads get dirty fast. Some of the dirt ends up in the pads and some of the dirt drops to the bottom of the carpet. The modern VLM chemicals are good at breaking the bond the dirt has with your carpet fibers.
Your Pristine guy with the 1960s dry foam method agitates a dry foam into the carpet and then kinda vacuums it up right away. Dog body oil and hair are not well handled by dry foam.---he is probably using modern chemicals and it appears he is just agitating the chems into the carpet. Often this will look pretty good. No dirt has been removed---the question you asked----the bond has broken and the chemical and dirt have fallen to the bottom of the carpet.
The HWE guys vaccum, put chems down and sometimes agitate and then use hot 180-215 degree water with good suction to pull the dirt out of the carpet. The water they leave is quite dirty and normally falls to the bottom of the carpet. The better the suction of the truckmount and skill of the operator the less dirty water left in your carpet.
The main problem with the Rug doctor is the very small capacity---you know about that----and the lack of agitation. (the little brush on the rug doc is a joke) Pristine put chems down and agitated pretty well. You came along with the rug doctor and were able to use his chems and agitation and pull a lot of the dirt back up. I don't know if you would have done as good of a job if he hadn't gone before you----rin
Most the HWE guys will go through 10-20 gallons of water per room depending on their system and how dirty the rooms are. Most home owners are not likely to fill the rug doctor 4 or 5 times in one room.
A
CRB (counter rotating Brush machine) is the latest rage in carpet cleaning for a couple of reasons. It is two brush rollers going in opposite directions fighting each other. They do a great job of getting the chems to break the dirt's bonds to your fiber and they lift a ton of dog hair and junk out of the carpet----way more than vacuuming the carpet 4 or 5 times will do.
If I were trying to get my carpets cleaned and had two house dogs I would ask the potential cleaner 1. do you have a truck mount and 2 do you use a
CRB to agitate. If he says yes to both ---hire him and be there when he does the job.
Good luck
Not all these guys will agree with me----