There is some I get from Lowes I think, it says "professional" on it and the bag is white and yellow, it does a good job. Last year I used some kind from spectracide, and it looked more like bug killer granules, but it worked good too, and it killed weeds that were emerged too.

When I see crab grass, I grab a flat head screw driver and dig it up/out. When I bought my house in 2015, I had a neighbor with a hoopdie mower and a yard to match. I have steadly increased my crab grass free buffer zone between that yard and mine. My new neighbor works on it, but he has an infestation. If you look you can see the line where my application stops, and it goes out as I walk around my HVAC unit outside. It's pretty funny.

I spot treat weeds in bermuda with Manor. I have seen my neighbor have his yard treated and it knocks the crabgrass back, but I am pretty convinced if you have alot of it, you need to dig it up by the roots. Wait til it rains and the ground is soft, and then it comes out really easy with a screw driver.