Hey Keith I have had good results with the vacaway products, the more stains I encountered the better I got at using the correct stain remover and application, vacaway has a guide to different stains and how to remove them, however I find that having a supply of "helgel orange" for sticky stains, gum, tar, etc works well, and then I use "spot n boost" regularly for stubborn stains, and it works great. I personally let the customer know what they can expect because all stains are not removable, but most are with the right product. I don't know if their are green products that are strong enough for stubborn stains, I usually explain to those who care that my primary cleaner is plant based, and that we only use stronger cleaners on the tough stains, have never had an issue, I think most people would just rather get their stains out, rather than make sure all your products are green. Good luck man
P.S. I only use the fiber plus pads on really trashed carpet and really bad traffic lanes, I don't believe increasing your agitation is going to help get a stain out if you haven't applied a cleaner that will work on it.
Dwell time makes a difference, often at resd jobs I will go in and pre-spray and hit spots and heavy traffic with quite a bit more spray. This way the spray has plenty of time before I bring in equipment and begin cleaning. I use oil eater on really trashed carpet then follow up with hydroxi pro. works wonders for us. sometimes ill bring out an iron with a pad underneath, just dont leave the iron there to long! good luck