I use this in all my purses and put feet on the bottoms. I punch a small hole for each of the foot prongs and up through the plastic canvas and it holds it in well. I wash my purses and they come out fine. I also make a bottom of a stiff cardboard or simular product and cover it with the same material as the purse to put on the bottom. When I wash them I pull the bottom piece out.
As for standing up while being filled, I think boning would work. Just make slots for several, open at the top so they can be taken out for washing!