The craftsman does not no-clip. The craftsman fixes the clip. They tighten the joint, sand the edge, recompile the shader. Where the player sees a wall to phase through, the craftsman sees a missing collision box—a mistake to be corrected.
Use the ender-beads item and repeatedly push them into the character's stomach (avoiding other interaction points).
Cause the Creeper character to reach max hearts and explode. Fireworks!
You have now completed Clip #1 toward the achievement.
Now go forth and clip through reality. Just remember to save your game first.
The primary method to trigger this achievement involves "breaking" the enderbeads to cause a teleportation or clipping effect:
: Fire a lit firework toy so that it penetrates a character from the outside.