Last week I pulled out some of my homemade newspaper planting pots from their tray. They are working great! As you can see in the picture, the roots are coming out of the side of the pots.
That is exactly what is supposed to happen with planting pots. It prevents the roots from becoming root bound - there is no reason to loosen up the roots, possibly damaging them, before planting the plants.
When I go to plant these, I will just stick planting pot and all into the garden. The roots will continue to grow out of the pot, and the newspaper will decompose in the soil.
I will definitely do this again next year!