I had a bad outbreak of the Eurasian milfoil too. Nearly choked out the pond. Not sure if it came in the water with some forage species that I stocked or if it transferred on a bird but it is not nice stuff. It did make my water very very clear while it was growing though! (It was spreading rapidly in this picture)
I used Sonar (pricey, and have some left if you want a good deal) You have to use it on a body of water that has stable amount of water (limited rain and limited flow in and flow out of water) to keep stable concentrations for 30days. I can't speak to what happens if you swim in the pond. Some of the pond experts here can talk about proper use of Sonar.
It worked great and no dead fish. I did late summer application and then a reapplication in the spring to catch any that would try to grow again and have had none since. I have a small pond so didn't need very much at all and would love to get what I have into the hands of someone else who needs it rather than store it on my shelf for years and years.