Question
Hi..in reading your answers here I just purchased a dethatching liquid from the Natures Lawn web site. My question is, once applied and used every 3 weeks as suggested, how long until I begin to see results, such as thatch turning to humus? I have a sod lawn and from what I understand Kentucky Blue Grass sod comes with a built in thatch layer. Thanks for your time.

Answer
I have no experience with that method of dethatching.
This I do know. The composting of vegetable matter requires the action of soil dwelling organisms. These organisms are most active within  a certain temperature range. They require organic matter to thrive. These are the chief reasons why we leave clippings on the lawn in summer but may prefer to bag in winter and why we apply organic products like "Milorganite" in the warmer months of the year.
Now I am guessing. The only of the above products that can be sold in a bottle are the bacteria. They will most likely be in a nutrient solution to ensure that they are alive and capable of functioning when you apply the product. So it behoves you to apply the product when the temperature is right (season) and organic matter is present (you can put it there).
So there you have it; all that I know and what I am guessing at. The label will tell you more than I can.
My favorite disclaimer is, "My advice is always free; you are under no obligation to take it."