Try to find someone with a pesticide license and get them to buy you Aquathol or Diquat(Reward). Grass carp are another option but they will only eat it if there is nothing else to eat and it will take a lot of carp and a lot of time. Hope this helps.
charlie, In Kentucky where my wife's from they use something called BLUESTONE. It kills pond grass and moss. I've seen one pond on hwy 58 out side south hill that had it. It turns the water light blue for awhile. DOES NOT hurt the fish
I had it bad in my pond and the only way to get rid of it was to drain it. I cut my banks straight down to about six feet and i havnt had any trouble with the grass.