Trash bag parachutes

I've got a couple rockets just about finished and ready for parachutes. I wondered today if anyone had experience using trash bags. I mean just the natural shape of the bag. I did a few searches and found dozens of sites talking about cutting circles or hexagons out of trash bags. But no one did anything like what I was thinking- just cut, say, a regular kitchen bag down shorter than normal, turn it upside down, mark 6 equally spaced spots around the bottom, reinforce with labels, punch holes and tie strings on.

Has anyone ever done this? It seems like it would be a cheap and dirty way to a hemispherical plastic chute. Is it that easy or have I missed something that would screw it up?

10foot:
Short answer is yeap you can do it that way. Had a number of my Scouts try using Black lawn and leaf bags as Chutes in the 80's & 90's.
they tend to be very unstable oscillating much more then flat plastic chutes even with very long (3 &4 time the diameter) shrouds and larger then normal spill holes. These were used mostly on sport flying "Estes" type C & D motor models with larger body diameters (BT-60 & Up) going to a bit over a pound LOWt.

We started with 6 shrouds but found Trashbags needed at least 12 to keep any kind of shape in the air.

cut them to shape and be done with them....8 sides and they work great!