1. Attach an inf factor to a depot.
2. Select the depot
3. Click on "Transfer factors from/to garrison"
4. Select the depot (not the garrison)
The game now shows the window shown below - note that both "to" and "from" are the depot.
5. Click the down arrow (marked in red below)
Now you have 2 inf factors on the depot effectively having double the one inf by magic.
6. Repeat steps 2-5 over and over to get as many inf as you care for
I have not attached a save game as this is consistently repeatable.


