Japanese Clover in Centipede

I have a pretty big infestation of Japanese clover in my centipede yard. It's widespread enough to where spot spraying is out of the question. I want something that I can broadcast that won't harm the grass. I have been using a mix of 2,4D, Atrazine, and surfactant with success but the area that needs to be treated is too much to handle with my small pump sprayer.

Thanks in advance for any help.

Yeah, I could have asked the home/garden board, but I like the answers that I get here better.

Peace