How can I walk around regularly while in the ground?
Solution 1:
I didn't run the command, i just read the OOC and guessing the the principle, hope that i am right.
The command is just teleport the player ~ ~-1 ~ first, so that the player is in the ground. Then, it is teleporting the player ~.00002 and ~-0.00002 in x and z direction repeatedly(positive for 1 time, in the next tick negative...), thus the player can pass through the border between each block.