Is there an erase function to erase a texture layer from terrain?

I use the Unity Terrain along with RTP. This means POM Shading and it is thus possible to see two layers drawn above each other. Is there a way to erase one texture layer from the splatmap with the unity terrain inspector?


Here you can see two layers stacked, but I only want grass.

Ah okay, I accidentally found a way by setting the target strength to 1 and painting grass again. The result is full grass.