my parents spray my weeds -
my dad mixes his own mixture b/c he works @ an elevator -
after he sprays you can literally stand there and watch them die!
I keep Keegan away from the areas overnite and reallllllly try to not walk on the areas where he sprayed b/c when I walk over that area and walk across the grass you can see my foot prints a day or so later!
The regular roundup from a store isn't that strong but if the yard is that bad - I would look into some kind of professional to work with it.