I too, wondered how best to use the Dunk when I got it.
I looked online... no information available anywhere.
At first I crumbled some Dunk and soaked it in a gallon of water. I figured this would do the job. Some Dunk fell on top of the soil in the pot and I left it there. Those were the first to be gnat free.
Then I figured out that I was doing this the hard way.
Since Dunk does not mind being dried out in between waterings, I decided to sprinkle on top of the pot.
My research with this product was all I had to go on.
Sprinkling on top of the pot worked GREAT! No more bothering with soaking in water for me!
Just water the Dunk in after applying, and ALL WILL BE FINE!
If this don't work I will give you all your money back! hahahahahaha
I am 110% certain this is a CURE. In a couple weeks you will have no more FUNGUS GNATS! EVER AGAIN!!!!
However, if you forget and bring in some new soil and forget to treat it! They will be back.
Pre-empt them with adding new DUNK to every new pot of soil you use and NO MORE GNATS!