The sweeping deadlift is one of my favorite overall exercises. Basically, it's a deadlift (or snatch deadlift which involves the lats even more) where you attach a resistance band to the bar and a post in front of you. The band is actively pulling the bar away from you so you need to engage the lats to keep the bar close to your body.
I like the wide, snatch-grip variation the most because you can pull the bar all the way into the hip crease while keeping the arms straight. This is exactly like doing a straight-arm pulldown, which is the best lat isolation exercise you can do.
What you want is to keep the bar close to you at all times. In the snatch variation in which you don't fully straighten the torso when the bar reaches the hips, the lats really have to work hard.
Hold the peak contraction 2 seconds per rep. And advanced variation is to finish the set by holding the bar in your hips as long as you can on the last rep.
Remember to focus on keeping the bar close to you throughout the movement. The key point is when you pass the knees. This is where the bar will tend to move away. So as you pass the knees, actively "sweep in" with the lats even harder.
Use a light bar weight and fairly hard band resistance to focus on strengthening the lats. Use a medium (70-80% of 1RM) bar weight with moderate band resistance to overload the whole back. Or use a heavy bar weight with light band resistance to practice integrating the lats in your heavy pulls. Either way, it's a formidable back exercise.