Vito,
In my neighborhood the organza bags were useful for about one week. The squirrels figured out right away and now specifically are looking for them.
What I do now is to use the plastic cups inside the larger size of the bags (or halves of the small water battles).
Otherwise the criters chew right through them.
Also, a spray of a Tabasco sauce over the bags helps a little too, I use 1 tbsp for a half gallon.