Shamatha/Zhine practitioner here. The wall staring practice described is not too unlike these. The main difference being that while practicing Zhine, I'm counting breathes.

I really want to point out that the purpose is not to concentrate so hard that focus remains. It's simply to be aware of attention drifting, and gently bring it back. Repeatedly, over time, this becomes easier and easier.

There is a sense of unwrinkling the mind that I achieve after a session. The inner voice drawing me toward the anxieties of life becomes quieter and quieter. The ability to choose to disregard thoughts and move on becomes stronger and stronger.