Unity grass (similar to UE4 kite demo)

Heya!

So if you have watched the UE4 kite demo you probably saw a lot of grass there. They released today a video where they explained how they did it but still I didn't catch the technique. Unity's own grass looks horrible but how about using the detail system? So by adding a detail mesh in terrain properties should it be possible to achieve similar results? I'm just interested in having a huge amount of grass, no the quality (because I can achieve the quality myself).

For you who haven't seen the kite demo: https://www.youtube.com/watch?v=w6EMc6eu3c8

And then the video where they explained how they did it: https://www.youtube.com/watch?v=clakekAHQx0&t=19

Hopefully someone knows a little bit more about Unity's terrain foliage/detail system!