I've been with chem dry for close to 30 years. Our cleaners don't leave that stuff behind. Looks to me something like host like Tanya said.
You may not ever get all that out even with vacuuming like crazy.
I'd like to know too, I'm looking in somewhat near future to have one too. I've thought about checking out various rug shops to see each ones setup. When I build it I want it to be right the first time & not wish I'd done it different.
I'm easing into it myself & have been accumulating equipment as I go as the need arises. As it is justified I put more into it but it has to pay for itself pretty quickly. If you've got unlimited funds go for it but I don't.
First thing I would do is take classes get some education if you...