sarrik said:
"...the real key is using the right cleaning products"
What is/are the right product(s) for this?
The filtration soil on each job is going to differ somewhat from the next job. It depends upon the source or combination of sources that polluted the air and got filtered out into the carpet.
My first choice would be to use Bridgepoint's Filter Free. It works well on a lot of jobs. The key is the chsrged hydrotope that counteracts van der Waals forces that hold small partilces to the carpet fiber.
Sometimes CTI's or
Prochems filter soil spotter will do the better job. So I usually carried at least 2 different filtration soil removers.
Some report good sucess using Fels Naptha. I never tried it. I believe it would leave residue.
Solvents, foam (for lubrication) and high heat are all helpful ingredients. So you may be sucessful using a prespray with plenty of solvent.