Of course there are companies propmoting their own products, hardly likely to get Robert Saunders recommending Solutions.
You will have to buy and try, or go for a well known, tried and tested product, or you could just buy the cheapest you can find and hope it works. It might be just as good as others.
Alltec did a training seminar with videos, one of which you got the client to look at while you cleaned their carpets, but that was about 10 years ago.