Wont use any other pre-spray again but Spiked
I added a little bit of grout Master to my pre-spray it worked really good cleaning some really dirty polyester carpet. The alkaline rinse is some of the best I've ever used I will continue using it.
I am very happy. Used Groutmaster for the first time, best tile and grout cleaner I have ever used.
I used this for the first time today on some commercial carpet that gets A LOT of foot traffic, food spills, coffee, etc. It knocked out stains better than anything I've used apart from a product I use only on really nasty stuff. This carpet is 16 yrs old at least and it cleaned it up great! Will be buying more soon!
Small sample, hard to really judge but first impressions are very good. Convincingly enough, just ordered a larger quantity for a second round to get a better test. Only wish you had a deodorizer sample to try.