Knife Project - Extrude through thickness? Is it possible to use the Knife Project tool to somehow cut through thickness and extrude the edges that are formed?
I'm trying to cut through these 4 faces (2 "cubes") but Knife Project only intercepts a hole into one face. I would like it to extrude the face through multiple planes.

Do I simply do this 4 times and connect the edges into faces manually?
Actually, you only need one single circle here instead of two.

First, after using Knife Project, find Cut Through on the lowerleft corner of the Toolshelf bar, or toggle it on the F6 panel.



Second, select each pair, then W ->  Bridge Edge Loops, to build faces between them (solidify the holes).