If you're looking for a way to remove those Bot eggs from your horses' coats, try this:
First spray the areas that have bot eggs with a fly repellant/insecticide. I like an oil based spray such as Horse and Pony (you can get it at TSC).
Using a disposable double edged razor, shave the eggs off. It's really simple and it works. You don't need to press hard, a light pressure is all you need because the eggs are attached on the ends of the hair. Of course you need to constantly wipe the hairs off the razor.
The reason I like the oil based spray is that it seems to make it easier to do the razor cut. The other reason is that I hope that if I miss any eggs, the insecticide in the spray will kill the egg...don't know that it will but it might.
If you've been having problems, I hope this helps.