Digging a hole in landscape smaller than 1 component

Hi, I want to dig a hole in my landscape so that I could have my character go down 6 steps lower than ground level. However, when I choose component brush, it makes a hole 10x bigger than the hole I need to dig underground. Furthermore, if I use a regular sculpt brush, the side walls are not completely flat, even after using the flatten brush.

Here is an example, to what I am trying to accomplish https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSM-Stw6NkHpPYJ-eKmohNTl-XHAVOqfgw-90eWzoRfTdobG0dF

as you can see from the photo the opening which enters underground is too small for component selecting. Are there any other ideas?

Hello there,
You can paint a hole in landscape, using opacity mask. Check this link.