I have a new customer that wants me to overseed his yard, approx 6000 sq. ft. His existing grass is just a little thin. I plan to use the slice-seeder to first dethatch, remove the thatch, and then take the slice seeder back over it, this time with the seed. Do I have to put straw down? Is there some other top dressing that I could use that is not so "messy". Is a top dressing absolutely necessary? Any thoughts/suggestions on my plan listed above would be highly appreciated!