Thanks jason,
Yesterday evening I ended up brushing on GrazonPD (with halfpint as an surfactant) directly to the leaf and stems because I know it is very effective on willow trees. This method was very time consuming but I know I got good coverage and the plants are already wilting as of this morning.
I did not want to use killzall in case any got into the water and to the shoreline it may kill my grass and cause erosion.