Used in a few weeks old soda stains and cat barf cool, with excellent results. Then was a dirty old man who had left oil stains. It took three treatments, but have fallen more than the shadow of a stain. You really need to try to identify them. This stuff is the best I've found for carpet cleaning in place with reasonable smell and does not irritate the skin. Great product. Recommended.
I just bought a BISSELL Tough Pre treat Carpet Upholstery a few weeks ago and it came with a bottle of this Carpet Cleaning Supplies for stains. I was a bit dark and long set-in stains dog was not sure he ever would. I used the pre-treatment spray and we will take some time (say 3 minutes, I think, but were premeditated, some of mine one or two hours in advance). When I went through steam cleaning, I was surprised to see these places are full. You can not even tell they were there!
With a name like "pre-filter", my expectations were low for the use of this product. I was pleasantly surprised! I tried spot cleaning carpets and too many foam is too wet, or just do not get up stains. This material is the best place carpet cleaner on the market. In fact, I have not used my Bissell machine over a year (not too impressed), but the stain weekly use (I have a cat). I will definitely buy more of this!