how is your battle with cogon grass going?
i am battling the same species with different non chemical methods and i think with some success, although a lot of work goes into it.
in some areas i have tropical kudzu which is out-shading large cogon grass invaded areas. since the only crop in that corner of the land is some fruit trees and big rose myrtle bushes out-shading is not much of a problem. if kudzu goes into the trees i come with my scissors and feed the mulch bed under the trees
i don't mind if the rose myrtle does get overgrown since i need to cut it back for regrowth sometimes soon anyway. out-shading works pretty well!
in other areas i ripped the grass out by hand; painful, even with gloves. i think now i would just cut it down with scissors or if i don't care about other plants growing inbetween just mowe it down. then used the grass itself to mulch that area heavily and stuck cassava sticks in between which is growing nicely now, and trying to establish soy bean and butterfly pea there as well. every now and then i remove single new grass coming through the grass mulch by hand.
and then there are "lawn" areas where i just ripped it all out by hand and keep doing so when it comes up again so other grasses and clovers have a chance to grow first. basically i am starving the grass by not allowing it to get much sunlight.
it gave me huge compost piles lol! thanks to the peepee method it composts in a decent fashion.
i realized the extreme roots it forms are not bad at all, loosening the soil and adding some sort of plant matter even to a decent depth to it. so after/while starving the grass away halfway succesfully i think i can commence with no tilling cultivation pretty well.
today i went with scissors through the garden cleaning cogongrass from areas that are only 50% cogongrass 50% other weeds anymore
heavy tilling is in my oppinion not a great option since it doesn't need much for this grass to grow back anyway.
cultivating it away is what i would do.