To be honest. you are almost better off buying the 100ml pre-bagged version. I tried Boyd's Chemi-Bags and it ripped after the second recharge. "The Bag" holds 250ml of Purigen but by time you factor that in it is easier to just buy the 100ml.
Kensfish has it for $7.49. They also have best prices on Primer, etc so easy to find a way to hit $50 for free shipping.
I have cheap bags found on amazon, ultra fine. There are a few pieces that still come through the mesh, but since I don't mess with it often, a few pieces here and there don't bother me. I'm going to try the pantyhose idea next time I'm messing with them. (I don't leave them in my filters since all my tanks are planted.)