I spent a bundle on a herbicide to kill my clover called "tenacity", I have a mostly Zoysia grass yard. I mixed the poison with a surfactant and dye an sprayed 1/3 of the yard. I went back in the house to look at youtube videos on the stuff and found out that it kills zoysia. I instantly got out the water hose and tried to wash as much of it off the grass as I could, I ended up with a few bare patches but most of my grass was OK.
I found out I needed a product called SpeedZone for zoysia, I bought some an may use if if we get the sun to shine for a few days.