Clethodim would work for that. 12oz per acre or about 1oz per gallon. Buy Ams supreme and add first, and add surfactant at end.
AMS liquid. 3 quarts/acre or 4oz/gallon
NIS 8 oz/acre or 15ml/gallon
Clethodim is slow, it will take 2 to 3 weeks to kill the grass fully. Would probably mow the plot after grasses are dead.