If you aren't getting the desired result, Solu-Boost gives it more "Humph!"
I mix 60ml with 20 Litres in the Solution tank and spray via a Stinger... In 6 weeks I have added Solu-boost twice...
How many carpets have you actually cleaned since using it?
I find I revert back to UPR on carpets that are affected by wood burning stoves, coal fires and soot, but have had resounding success otherwise, using Fushion8....