I was playing around in the tutorial level when I placed down some green blocks. Once I did that, I ducked into them (I was in a slope) and I clipped under the ground. I have no footage of this but I'll try getting footage. Not sure if this can be used anywhere.

That has happened a few times to me, I clipped through one of the slanted pipes on pipe 3 with the boot, didn't do anything fancy though, I just slammed into the pipe and happened to clip into it, doesn't seem very useful though, maybe could be used in 200% if a clip through straight walls is found.