If you want to kill all the weeds, you could just rent a tractor with a grating attachment and drag it over the yard to get to the bottom layer of dirt then haul away the extra dirt you grated so that there is no space for them to grow.
Not big enough areas for tractor unless I do my whole weedy yard. LOL
Would never work anyway. If you kill everything, the weeds are first thing to come back. I am getting some grass seed down right away, so should look better in a couple weeks.