The biggest hint I can give on using BOK products is to ignore the labeling. You have to use way more product than the say. PreSpray must be 4 oz per RTU or more.
Bac out is great for - Upholstery pre-spray - especially on cottons, linens and such. It's very much a "do no harm" product. Expensive but worth it in my opinion. Customers love it. Also good as a "do no harm" spotter for food, wine, pet spots. It's magic on cat vomit. Actually it's kind of weird how well it works on it. It just vanishes. (or maybe the dog ate it?)
Fiber glow powder is okay as a rinse, but it's foamy. It has a lot of sodium percarbonate in it, which I believe is doing most of the heavy lifting. And not very strong. I don't normally use rinses so I don't use it at all anymore.
Fiber glow liquid is good as a pre-spray, but you have to boost it with some Sodium percarbonate to get it to work well. You will need lots. They sell an oxy-bleach. It is reasonably priced. I recommend at least 1 oz per gallon of RTU. You will also have to boost with either their citus soy solvent or another citrus product if there is the carpet is even slightly oily.
Personally I think it works reasonably well on most carpet if properly boosted, and rinsed with a really hot machine.
The POG must be followed with some sort of detergent to rinse out the solvent. It works slowly but well on gum and and oddly enough some wax. A small bottle of it goes a very, very long way.
All that said, I have switched over to Planet Guard prespray. for many of my jobs. I still keep some on board for the truly chemically sensitive and regular customers how have become accustomed to it.