Okay, so I've conducted a clinical trial. I purchased three of the recommended "carpet drugs" that were suggested for the treatment of impacted chicken poop.
Here are the results:
This is the carpet before I started. It had been sprayed with Spot shot, vacuumed and steam cleaned.
The drugs, next to their respective cleaned stains.
For ease of use : 1) Folex. 2) Woolite Oxy 3) Oxyclean
The only reason Oxyclean was a little harder to use was that I had to make a paste and rub it in (it actually turns hot in your hand when you add water! SO COOL!) The Woolite Oxy was harder to use because you have to keep it tilted at a certain angle. Folex simply allows you to spray and blot. No rinsing.
For ultimate cleaning power 1) Oxyclean 2) Folex 3) Woolite Oxy
Now, in all fairness to Folex, its stain was much darker and a little larger than the others.
After it sat for about five minutes, the stain was removed completely. I used it later that day to clean out some cat vomit, and it performed admirably.
However, when all three were used on fresh mango stains, none removed the stain.
Smell: Now, none of these smelled at all, since they had been cleaned already. But, as far as the cleaners' actual smell goes 1) Woolite Oxy 2) Oxyclean 3) Folex.
Both Oxyclean and Folex have a sort of organic smell to them--but since Woolite Oxy is marketed for pet stains, it also has a deodorizer in it.