Step 1. grab any male citizen model and hold out your physgun

Step 2. go about 30 ft in the air

Step 3. grab the citizen by the upper body (anywhere else doesn't work) and start descending (while still in no clip)

Step 4. once his upper body is in the ground, freeze it and you're done.

NOTES:
1. stay above ground as if you go in the floor it doesn't work
2. you can unfreeze him after so he retains his ragdoll capabilities (you can also pull him out of the ground here too)